diff --git a/src/tint/reader/spirv/construct.cc b/src/tint/reader/spirv/construct.cc
index 23808e1484..2307c24d45 100644
--- a/src/tint/reader/spirv/construct.cc
+++ b/src/tint/reader/spirv/construct.cc
@@ -14,9 +14,7 @@
 
 #include "src/tint/reader/spirv/construct.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 Construct::Construct(const Construct* the_parent,
                      int the_depth,
@@ -65,6 +63,4 @@ Construct::Construct(const Construct* the_parent,
       end_pos(the_end_pos),
       scope_end_pos(the_scope_end_pos) {}
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/construct.h b/src/tint/reader/spirv/construct.h
index 898b682104..fbefc8fa84 100644
--- a/src/tint/reader/spirv/construct.h
+++ b/src/tint/reader/spirv/construct.h
@@ -20,9 +20,7 @@
 #include <string>
 #include <vector>
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// A structured control flow construct, consisting of a set of basic blocks.
 /// A construct is a span of blocks in the computed block order,
@@ -271,8 +269,6 @@ inline std::string ToString(const ConstructList& cl) {
   return ss.str();
 }
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_CONSTRUCT_H_
diff --git a/src/tint/reader/spirv/entry_point_info.cc b/src/tint/reader/spirv/entry_point_info.cc
index 5258606d74..2677494a12 100644
--- a/src/tint/reader/spirv/entry_point_info.cc
+++ b/src/tint/reader/spirv/entry_point_info.cc
@@ -16,9 +16,7 @@
 
 #include <utility>
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 EntryPointInfo::EntryPointInfo(std::string the_name,
                                ast::PipelineStage the_stage,
@@ -39,6 +37,4 @@ EntryPointInfo::EntryPointInfo(const EntryPointInfo&) = default;
 
 EntryPointInfo::~EntryPointInfo() = default;
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/entry_point_info.h b/src/tint/reader/spirv/entry_point_info.h
index e65b79d826..374bd8302a 100644
--- a/src/tint/reader/spirv/entry_point_info.h
+++ b/src/tint/reader/spirv/entry_point_info.h
@@ -20,9 +20,7 @@
 
 #include "src/tint/ast/pipeline_stage.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// The size of an integer-coordinate grid, in the x, y, and z dimensions.
 struct GridSize {
@@ -88,8 +86,6 @@ struct EntryPointInfo {
   GridSize workgroup_size;
 };
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_ENTRY_POINT_INFO_H_
diff --git a/src/tint/reader/spirv/enum_converter.cc b/src/tint/reader/spirv/enum_converter.cc
index a197bac360..2cd1daa883 100644
--- a/src/tint/reader/spirv/enum_converter.cc
+++ b/src/tint/reader/spirv/enum_converter.cc
@@ -14,9 +14,7 @@
 
 #include "src/tint/reader/spirv/enum_converter.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 EnumConverter::EnumConverter(const FailStream& fs) : fail_stream_(fs) {}
 
@@ -177,6 +175,4 @@ ast::TexelFormat EnumConverter::ToTexelFormat(SpvImageFormat fmt) {
   return ast::TexelFormat::kNone;
 }
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/enum_converter.h b/src/tint/reader/spirv/enum_converter.h
index d2caac3357..4a31cfec11 100644
--- a/src/tint/reader/spirv/enum_converter.h
+++ b/src/tint/reader/spirv/enum_converter.h
@@ -22,9 +22,7 @@
 #include "src/tint/reader/spirv/fail_stream.h"
 #include "src/tint/sem/storage_texture_type.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// A converter from SPIR-V enums to Tint AST enums.
 class EnumConverter {
@@ -74,8 +72,6 @@ class EnumConverter {
   FailStream fail_stream_;
 };
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_ENUM_CONVERTER_H_
diff --git a/src/tint/reader/spirv/enum_converter_test.cc b/src/tint/reader/spirv/enum_converter_test.cc
index eec14f393c..6f9e2a17e5 100644
--- a/src/tint/reader/spirv/enum_converter_test.cc
+++ b/src/tint/reader/spirv/enum_converter_test.cc
@@ -18,9 +18,7 @@
 
 #include "gmock/gmock.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 // Pipeline stage
@@ -424,6 +422,4 @@ INSTANTIATE_TEST_SUITE_P(
         TexelFormatCase{SpvImageFormatRg8ui, false, ast::TexelFormat::kNone}));
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/fail_stream.h b/src/tint/reader/spirv/fail_stream.h
index a7530ca724..6160de8f00 100644
--- a/src/tint/reader/spirv/fail_stream.h
+++ b/src/tint/reader/spirv/fail_stream.h
@@ -17,9 +17,7 @@
 
 #include <ostream>
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// A FailStream object accumulates values onto a given std::ostream,
 /// and can be used to record failure by writing the false value
@@ -67,8 +65,6 @@ class FailStream {
   std::ostream* out_;
 };
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_FAIL_STREAM_H_
diff --git a/src/tint/reader/spirv/fail_stream_test.cc b/src/tint/reader/spirv/fail_stream_test.cc
index 4c6e9bf9e9..13c35e563c 100644
--- a/src/tint/reader/spirv/fail_stream_test.cc
+++ b/src/tint/reader/spirv/fail_stream_test.cc
@@ -16,9 +16,7 @@
 
 #include "gmock/gmock.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -68,6 +66,4 @@ TEST_F(FailStreamTest, ShiftOperatorAccumulatesValues) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function.cc b/src/tint/reader/spirv/function.cc
index c130e85383..3ee9159c80 100644
--- a/src/tint/reader/spirv/function.cc
+++ b/src/tint/reader/spirv/function.cc
@@ -137,9 +137,7 @@
 //           constructs
 //
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 namespace {
 
@@ -6143,9 +6141,7 @@ bool FunctionEmitter::IsFloatOne(uint32_t value_id) {
 FunctionEmitter::FunctionDeclaration::FunctionDeclaration() = default;
 FunctionEmitter::FunctionDeclaration::~FunctionDeclaration() = default;
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 TINT_INSTANTIATE_TYPEINFO(tint::reader::spirv::StatementBuilder);
 TINT_INSTANTIATE_TYPEINFO(tint::reader::spirv::SwitchStatementBuilder);
diff --git a/src/tint/reader/spirv/function.h b/src/tint/reader/spirv/function.h
index 46b36caedf..e90de21e68 100644
--- a/src/tint/reader/spirv/function.h
+++ b/src/tint/reader/spirv/function.h
@@ -26,9 +26,7 @@
 #include "src/tint/reader/spirv/construct.h"
 #include "src/tint/reader/spirv/parser_impl.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// Kinds of CFG edges.
 //
@@ -1297,8 +1295,6 @@ class FunctionEmitter {
   const EntryPointInfo* ep_info_ = nullptr;
 };
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_FUNCTION_H_
diff --git a/src/tint/reader/spirv/function_arithmetic_test.cc b/src/tint/reader/spirv/function_arithmetic_test.cc
index 8b0ed5de7f..c48f86dd39 100644
--- a/src/tint/reader/spirv/function_arithmetic_test.cc
+++ b/src/tint/reader/spirv/function_arithmetic_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::HasSubstr;
@@ -1080,6 +1078,4 @@ TEST_F(SpvUnaryArithTest, Transpose_3x2) {
 // TODO(dneto): OpSMulExtended
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_bit_test.cc b/src/tint/reader/spirv/function_bit_test.cc
index 722cc2abb9..ba0e67ea3f 100644
--- a/src/tint/reader/spirv/function_bit_test.cc
+++ b/src/tint/reader/spirv/function_bit_test.cc
@@ -16,9 +16,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::HasSubstr;
@@ -1046,6 +1044,4 @@ TEST_F(SpvUnaryBitTest, ExtractBits_UintVector) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_call_test.cc b/src/tint/reader/spirv/function_call_test.cc
index bfc4eabdcd..6aba922bc1 100644
--- a/src/tint/reader/spirv/function_call_test.cc
+++ b/src/tint/reader/spirv/function_call_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -197,6 +195,4 @@ fn x_100() {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_cfg_test.cc b/src/tint/reader/spirv/function_cfg_test.cc
index ce36521a20..bd3c98c896 100644
--- a/src/tint/reader/spirv/function_cfg_test.cc
+++ b/src/tint/reader/spirv/function_cfg_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -13224,6 +13222,4 @@ TEST_F(SpvParserCFGTest,
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_composite_test.cc b/src/tint/reader/spirv/function_composite_test.cc
index e11b0f0b8e..8b29a908c9 100644
--- a/src/tint/reader/spirv/function_composite_test.cc
+++ b/src/tint/reader/spirv/function_composite_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -1070,6 +1068,4 @@ TEST_F(SpvParserTest, DISABLED_WorkgroupSize_Overridable) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_conversion_test.cc b/src/tint/reader/spirv/function_conversion_test.cc
index 1dffd35702..4d77997159 100644
--- a/src/tint/reader/spirv/function_conversion_test.cc
+++ b/src/tint/reader/spirv/function_conversion_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -650,6 +648,4 @@ OpFunctionEnd
 // TODO(dneto): OpSatConvertUToS // Kernel (OpenCL), not in WebGPU
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_decl_test.cc b/src/tint/reader/spirv/function_decl_test.cc
index e30930ddbe..5fa6330fe4 100644
--- a/src/tint/reader/spirv/function_decl_test.cc
+++ b/src/tint/reader/spirv/function_decl_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::HasSubstr;
@@ -151,6 +149,4 @@ TEST_F(SpvParserTest, Emit_GenerateParamNames) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_glsl_std_450_test.cc b/src/tint/reader/spirv/function_glsl_std_450_test.cc
index ce16f138a8..7d7a485dcf 100644
--- a/src/tint/reader/spirv/function_glsl_std_450_test.cc
+++ b/src/tint/reader/spirv/function_glsl_std_450_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::HasSubstr;
@@ -1172,6 +1170,4 @@ TEST_F(SpvParserTest, GlslStd450_Ldexp_Vector_Floatvec_Uintvec) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_logical_test.cc b/src/tint/reader/spirv/function_logical_test.cc
index 23dc5c46d7..2d2e4e9322 100644
--- a/src/tint/reader/spirv/function_logical_test.cc
+++ b/src/tint/reader/spirv/function_logical_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::HasSubstr;
@@ -987,6 +985,4 @@ TEST_F(SpvLogicalTest, IsInf_Vector) {
 // TODO(dneto): OpSelect over more general types, as in SPIR-V 1.4
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_memory_test.cc b/src/tint/reader/spirv/function_memory_test.cc
index 8e722bdf84..33fa2f59d0 100644
--- a/src/tint/reader/spirv/function_memory_test.cc
+++ b/src/tint/reader/spirv/function_memory_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -1290,6 +1288,4 @@ TEST_F(SpvParserMemoryTest, InvalidPointer_ConstantNull_IsError) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_misc_test.cc b/src/tint/reader/spirv/function_misc_test.cc
index 582ff8d50d..e64eb2e668 100644
--- a/src/tint/reader/spirv/function_misc_test.cc
+++ b/src/tint/reader/spirv/function_misc_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -343,6 +341,4 @@ TEST_F(SpvParserTest, ValueFromBlockNotInBlockOrder) {
 // TODO(dneto): OpSizeof : requires Kernel (OpenCL)
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/function_var_test.cc b/src/tint/reader/spirv/function_var_test.cc
index ddec083ecc..c6c1aa515e 100644
--- a/src/tint/reader/spirv/function_var_test.cc
+++ b/src/tint/reader/spirv/function_var_test.cc
@@ -17,9 +17,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -1670,6 +1668,4 @@ TEST_F(SpvParserFunctionVarTest, DISABLED_EmitStatement_Hoist_UsedAsPtrArg) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/namer.cc b/src/tint/reader/spirv/namer.cc
index ab19bb475c..6e7044f0f2 100644
--- a/src/tint/reader/spirv/namer.cc
+++ b/src/tint/reader/spirv/namer.cc
@@ -20,9 +20,7 @@
 
 #include "src/tint/debug.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 namespace {
 
@@ -234,6 +232,4 @@ void Namer::ResolveMemberNamesForStruct(uint32_t struct_id,
   }
 }
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/namer.h b/src/tint/reader/spirv/namer.h
index 5491152c9d..fa5fc3a7e9 100644
--- a/src/tint/reader/spirv/namer.h
+++ b/src/tint/reader/spirv/namer.h
@@ -21,9 +21,7 @@
 
 #include "src/tint/reader/spirv/fail_stream.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// A Namer maps SPIR-V IDs to strings.
 ///
@@ -158,8 +156,6 @@ class Namer {
   std::unordered_map<std::string, uint32_t> next_unusued_derived_name_id_;
 };
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_NAMER_H_
diff --git a/src/tint/reader/spirv/namer_test.cc b/src/tint/reader/spirv/namer_test.cc
index 0aee67db10..62cf56d3f4 100644
--- a/src/tint/reader/spirv/namer_test.cc
+++ b/src/tint/reader/spirv/namer_test.cc
@@ -16,9 +16,7 @@
 
 #include "gmock/gmock.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -402,6 +400,4 @@ INSTANTIATE_TEST_SUITE_P(SpvParserTest_ReservedWords,
                          }));
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser.cc b/src/tint/reader/spirv/parser.cc
index 32f00afec7..ebb5bc4d92 100644
--- a/src/tint/reader/spirv/parser.cc
+++ b/src/tint/reader/spirv/parser.cc
@@ -24,9 +24,7 @@
 #include "src/tint/transform/simplify_pointers.h"
 #include "src/tint/transform/unshadow.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 Program Parse(const std::vector<uint32_t>& input) {
   ParserImpl parser(input);
@@ -60,6 +58,4 @@ Program Parse(const std::vector<uint32_t>& input) {
   return manager.Run(&program).program;
 }
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser.h b/src/tint/reader/spirv/parser.h
index 2e5a5c24e1..3641e08daa 100644
--- a/src/tint/reader/spirv/parser.h
+++ b/src/tint/reader/spirv/parser.h
@@ -19,9 +19,7 @@
 
 #include "src/tint/program.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// Parses the SPIR-V source data, returning the parsed program.
 /// If the source data fails to parse then the returned
@@ -31,8 +29,6 @@ namespace spirv {
 /// @returns the parsed program
 Program Parse(const std::vector<uint32_t>& input);
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_PARSER_H_
diff --git a/src/tint/reader/spirv/parser_impl.cc b/src/tint/reader/spirv/parser_impl.cc
index c2f50d39fc..6cf8e7a998 100644
--- a/src/tint/reader/spirv/parser_impl.cc
+++ b/src/tint/reader/spirv/parser_impl.cc
@@ -32,9 +32,7 @@
 #include "src/tint/sem/sampled_texture_type.h"
 #include "src/tint/utils/unique_vector.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 namespace {
 
@@ -2791,6 +2789,4 @@ WorkgroupSizeInfo::WorkgroupSizeInfo() = default;
 
 WorkgroupSizeInfo::~WorkgroupSizeInfo() = default;
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl.h b/src/tint/reader/spirv/parser_impl.h
index ee31004255..d871452a7a 100644
--- a/src/tint/reader/spirv/parser_impl.h
+++ b/src/tint/reader/spirv/parser_impl.h
@@ -51,9 +51,7 @@
 /// familiar to Vulkan SPIR-V developers.  We will tend to use "image"
 /// and "sampler" instead of "handle".
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// The binary representation of a SPIR-V decoration enum followed by its
 /// operands, if any.
@@ -881,8 +879,6 @@ class ParserImpl : Reader {
   WorkgroupSizeInfo workgroup_size_builtin_;
 };
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_PARSER_IMPL_H_
diff --git a/src/tint/reader/spirv/parser_impl_barrier_test.cc b/src/tint/reader/spirv/parser_impl_barrier_test.cc
index a718ab3f16..39f267f193 100644
--- a/src/tint/reader/spirv/parser_impl_barrier_test.cc
+++ b/src/tint/reader/spirv/parser_impl_barrier_test.cc
@@ -19,9 +19,7 @@
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 #include "src/tint/sem/call.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -208,6 +206,4 @@ TEST_F(SpvParserTest, ErrStorageBarrierInvalidMemory) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_convert_member_decoration_test.cc b/src/tint/reader/spirv/parser_impl_convert_member_decoration_test.cc
index 245e0e84d9..adc33971cf 100644
--- a/src/tint/reader/spirv/parser_impl_convert_member_decoration_test.cc
+++ b/src/tint/reader/spirv/parser_impl_convert_member_decoration_test.cc
@@ -15,9 +15,7 @@
 #include "gmock/gmock.h"
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -152,6 +150,4 @@ TEST_F(SpvParserTest, ConvertMemberDecoration_UnhandledDecoration) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_convert_type_test.cc b/src/tint/reader/spirv/parser_impl_convert_type_test.cc
index 7bdae7a068..bbda414377 100644
--- a/src/tint/reader/spirv/parser_impl_convert_type_test.cc
+++ b/src/tint/reader/spirv/parser_impl_convert_type_test.cc
@@ -16,9 +16,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -930,6 +928,4 @@ TEST_F(SpvParserTest, ConvertType_SampledImage_PretendVoid) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_function_decl_test.cc b/src/tint/reader/spirv/parser_impl_function_decl_test.cc
index b664dd1273..4e10725e6d 100644
--- a/src/tint/reader/spirv/parser_impl_function_decl_test.cc
+++ b/src/tint/reader/spirv/parser_impl_function_decl_test.cc
@@ -16,9 +16,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::HasSubstr;
@@ -470,6 +468,4 @@ TEST_F(SpvParserTest, EmitFunctions_GenerateParamNames) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_get_decorations_test.cc b/src/tint/reader/spirv/parser_impl_get_decorations_test.cc
index 92652e405c..5f4f971472 100644
--- a/src/tint/reader/spirv/parser_impl_get_decorations_test.cc
+++ b/src/tint/reader/spirv/parser_impl_get_decorations_test.cc
@@ -16,9 +16,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -261,6 +259,4 @@ TEST_F(SpvParserGetDecorationsTest, GetDecorationsForMember_RestrictPointer) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_handle_test.cc b/src/tint/reader/spirv/parser_impl_handle_test.cc
index a2e99adaec..d1938aa91d 100644
--- a/src/tint/reader/spirv/parser_impl_handle_test.cc
+++ b/src/tint/reader/spirv/parser_impl_handle_test.cc
@@ -19,9 +19,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -3918,6 +3916,4 @@ return;
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_import_test.cc b/src/tint/reader/spirv/parser_impl_import_test.cc
index 65fac1c36b..852c08ad06 100644
--- a/src/tint/reader/spirv/parser_impl_import_test.cc
+++ b/src/tint/reader/spirv/parser_impl_import_test.cc
@@ -16,9 +16,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::ElementsAre;
@@ -123,6 +121,4 @@ TEST_F(SpvParserImportTest, Import_NonSemantic_IgnoredExtInsts) {
 // imports.
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_module_var_test.cc b/src/tint/reader/spirv/parser_impl_module_var_test.cc
index 236840b263..d50959dd52 100644
--- a/src/tint/reader/spirv/parser_impl_module_var_test.cc
+++ b/src/tint/reader/spirv/parser_impl_module_var_test.cc
@@ -18,9 +18,7 @@
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 #include "src/tint/utils/string.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using SpvModuleScopeVarParserTest = SpvParserTest;
@@ -5284,6 +5282,4 @@ fn main(@location(1) @interpolate(flat) x_1_param : u32, @location(2) @interpola
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_named_types_test.cc b/src/tint/reader/spirv/parser_impl_named_types_test.cc
index fcc04c58e8..53366e64a2 100644
--- a/src/tint/reader/spirv/parser_impl_named_types_test.cc
+++ b/src/tint/reader/spirv/parser_impl_named_types_test.cc
@@ -16,9 +16,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::HasSubstr;
@@ -154,6 +152,4 @@ type Arr_1 = @stride(8) array<u32, 5u>;
 // Blocked by crbug.com/tint/32
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_test.cc b/src/tint/reader/spirv/parser_impl_test.cc
index f50b73e279..237bb67a3b 100644
--- a/src/tint/reader/spirv/parser_impl_test.cc
+++ b/src/tint/reader/spirv/parser_impl_test.cc
@@ -16,9 +16,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::HasSubstr;
@@ -223,6 +221,4 @@ TEST_F(SpvParserTest, Impl_IsValidIdentifier) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_impl_test_helper.cc b/src/tint/reader/spirv/parser_impl_test_helper.cc
index c11304882f..bc62973fdc 100644
--- a/src/tint/reader/spirv/parser_impl_test_helper.cc
+++ b/src/tint/reader/spirv/parser_impl_test_helper.cc
@@ -15,10 +15,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/writer/wgsl/generator_impl.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
-namespace test {
+namespace tint::reader::spirv::test {
 
 // Default to not dumping the SPIR-V assembly.
 bool ParserImplWrapperForTest::dump_successfully_converted_spirv_ = false;
@@ -79,7 +76,4 @@ std::string ToString(const Program& program, const ast::Node* node) {
   return writer.result();
 }
 
-}  // namespace test
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv::test
diff --git a/src/tint/reader/spirv/parser_impl_test_helper.h b/src/tint/reader/spirv/parser_impl_test_helper.h
index f9a6c3efb1..9c270301e0 100644
--- a/src/tint/reader/spirv/parser_impl_test_helper.h
+++ b/src/tint/reader/spirv/parser_impl_test_helper.h
@@ -34,9 +34,7 @@
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 #include "src/tint/reader/spirv/usage.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace test {
 
 /// A test class that wraps ParseImpl
@@ -312,8 +310,6 @@ class SpvParserTestBase : public T {
 // Use this form when you don't need to template any further.
 using SpvParserTest = SpvParserTestBase<::testing::Test>;
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_PARSER_IMPL_TEST_HELPER_H_
diff --git a/src/tint/reader/spirv/parser_impl_user_name_test.cc b/src/tint/reader/spirv/parser_impl_user_name_test.cc
index a8d821981e..65405127e4 100644
--- a/src/tint/reader/spirv/parser_impl_user_name_test.cc
+++ b/src/tint/reader/spirv/parser_impl_user_name_test.cc
@@ -16,9 +16,7 @@
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 #include "src/tint/reader/spirv/spirv_tools_helpers_test.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -210,6 +208,4 @@ TEST_F(SpvParserUserNameTest, EntryPointNames_DistinctFromInnerNames) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_test.cc b/src/tint/reader/spirv/parser_test.cc
index 3ae802f920..304eb3ec5e 100644
--- a/src/tint/reader/spirv/parser_test.cc
+++ b/src/tint/reader/spirv/parser_test.cc
@@ -16,9 +16,7 @@
 
 #include "gtest/gtest.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ParserTest = testing::Test;
@@ -35,6 +33,4 @@ TEST_F(ParserTest, DataEmpty) {
 // TODO(dneto): uint32 vec, invalid SPIR-V
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_type.cc b/src/tint/reader/spirv/parser_type.cc
index 805a10b9f9..7a3c97f1f8 100644
--- a/src/tint/reader/spirv/parser_type.cc
+++ b/src/tint/reader/spirv/parser_type.cc
@@ -45,9 +45,7 @@ TINT_INSTANTIATE_TYPEINFO(tint::reader::spirv::Named);
 TINT_INSTANTIATE_TYPEINFO(tint::reader::spirv::Alias);
 TINT_INSTANTIATE_TYPEINFO(tint::reader::spirv::Struct);
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 namespace {
 struct PointerHasher {
@@ -638,6 +636,4 @@ std::string Named::String() const {
 }
 #endif  // NDEBUG
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_type.h b/src/tint/reader/spirv/parser_type.h
index 2313e9ecfa..578f89fb3c 100644
--- a/src/tint/reader/spirv/parser_type.h
+++ b/src/tint/reader/spirv/parser_type.h
@@ -27,17 +27,15 @@
 #include "src/tint/castable.h"
 #include "src/tint/utils/block_allocator.h"
 
-// Forward declarations
+// Forward Declarations
 namespace tint {
 class ProgramBuilder;
 namespace ast {
 class Type;
-}  // namespace ast
+}
 }  // namespace tint
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// Type is the base class for all types
 class Type : public Castable<Type> {
@@ -604,8 +602,6 @@ class TypeManager {
   std::unique_ptr<State> state;
 };
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_PARSER_TYPE_H_
diff --git a/src/tint/reader/spirv/parser_type_test.cc b/src/tint/reader/spirv/parser_type_test.cc
index 1e90264812..bddfdc5aff 100644
--- a/src/tint/reader/spirv/parser_type_test.cc
+++ b/src/tint/reader/spirv/parser_type_test.cc
@@ -16,9 +16,7 @@
 
 #include "src/tint/reader/spirv/parser_type.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 TEST(SpvParserTypeTest, SameArgumentsGivesSamePointer) {
@@ -97,6 +95,4 @@ TEST(SpvParserTypeTest, DifferentArgumentsGivesDifferentPointer) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/spirv_tools_helpers_test.cc b/src/tint/reader/spirv/spirv_tools_helpers_test.cc
index a4862d0d83..057dffd55b 100644
--- a/src/tint/reader/spirv/spirv_tools_helpers_test.cc
+++ b/src/tint/reader/spirv/spirv_tools_helpers_test.cc
@@ -17,10 +17,7 @@
 #include "gtest/gtest.h"
 #include "spirv-tools/libspirv.hpp"
 
-namespace tint {
-namespace reader {
-namespace spirv {
-namespace test {
+namespace tint::reader::spirv::test {
 
 std::vector<uint32_t> Assemble(const std::string& spirv_assembly) {
   // TODO(dneto): Use ScopedTrace?
@@ -61,7 +58,4 @@ std::string Disassemble(const std::vector<uint32_t>& spirv_module) {
   return result;
 }
 
-}  // namespace test
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv::test
diff --git a/src/tint/reader/spirv/spirv_tools_helpers_test.h b/src/tint/reader/spirv/spirv_tools_helpers_test.h
index 929efd61ab..907f02f26e 100644
--- a/src/tint/reader/spirv/spirv_tools_helpers_test.h
+++ b/src/tint/reader/spirv/spirv_tools_helpers_test.h
@@ -18,10 +18,7 @@
 #include <string>
 #include <vector>
 
-namespace tint {
-namespace reader {
-namespace spirv {
-namespace test {
+namespace tint::reader::spirv::test {
 
 /// @param spirv_assembly SPIR-V assembly text
 /// @returns the SPIR-V module assembled from the given text.  Numeric IDs
@@ -32,9 +29,6 @@ std::vector<uint32_t> Assemble(const std::string& spirv_assembly);
 /// @returns the disassembled module
 std::string Disassemble(const std::vector<uint32_t>& spirv_module);
 
-}  // namespace test
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv::test
 
 #endif  // SRC_TINT_READER_SPIRV_SPIRV_TOOLS_HELPERS_TEST_H_
diff --git a/src/tint/reader/spirv/usage.cc b/src/tint/reader/spirv/usage.cc
index 28aec49354..2ddb696f16 100644
--- a/src/tint/reader/spirv/usage.cc
+++ b/src/tint/reader/spirv/usage.cc
@@ -16,9 +16,7 @@
 
 #include <sstream>
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 Usage::Usage() {}
 Usage::Usage(const Usage& other) = default;
@@ -189,6 +187,4 @@ std::string Usage::to_str() const {
   return ss.str();
 }
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/usage.h b/src/tint/reader/spirv/usage.h
index f2686e75f7..df6783f456 100644
--- a/src/tint/reader/spirv/usage.h
+++ b/src/tint/reader/spirv/usage.h
@@ -17,9 +17,7 @@
 
 #include <string>
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 
 /// Records the properties of a sampler or texture based on how it's used
 /// by image instructions inside function bodies.
@@ -130,8 +128,6 @@ inline std::ostream& operator<<(std::ostream& out, const Usage& u) {
   return u.operator<<(out);
 }
 
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv
 
 #endif  // SRC_TINT_READER_SPIRV_USAGE_H_
diff --git a/src/tint/reader/spirv/usage_test.cc b/src/tint/reader/spirv/usage_test.cc
index 2c63e5fc23..0ee7f15fa0 100644
--- a/src/tint/reader/spirv/usage_test.cc
+++ b/src/tint/reader/spirv/usage_test.cc
@@ -18,9 +18,7 @@
 #include "gmock/gmock.h"
 #include "src/tint/reader/spirv/parser_impl_test_helper.h"
 
-namespace tint {
-namespace reader {
-namespace spirv {
+namespace tint::reader::spirv {
 namespace {
 
 using ::testing::Eq;
@@ -290,6 +288,4 @@ TEST_F(SpvParserTest, Usage_AddStorageWriteTexture) {
 }
 
 }  // namespace
-}  // namespace spirv
-}  // namespace reader
-}  // namespace tint
+}  // namespace tint::reader::spirv