P1467R9 Extended Floating-Point Types (#3583)

stl/CMakeLists.txt

@@ -201,6 +201,7 @@ set(HEADERS
     ${CMAKE_CURRENT_LIST_DIR}/inc/stack
     ${CMAKE_CURRENT_LIST_DIR}/inc/stacktrace
     ${CMAKE_CURRENT_LIST_DIR}/inc/stdexcept
+    ${CMAKE_CURRENT_LIST_DIR}/inc/stdfloat
     ${CMAKE_CURRENT_LIST_DIR}/inc/stop_token
     ${CMAKE_CURRENT_LIST_DIR}/inc/streambuf
     ${CMAKE_CURRENT_LIST_DIR}/inc/string

stl/inc/__msvc_all_public_headers.hpp

@@ -49,6 +49,7 @@
 #include <numbers>
 #include <ratio>
 #include <source_location>
+#include <stdfloat>
 #include <tuple>
 #include <type_traits>
 #include <utility>

stl/inc/header-units.json

@@ -107,6 +107,7 @@
         "stack",
         "stacktrace",
         "stdexcept",
+        "stdfloat",
         "stop_token",
         "streambuf",
         "string",

stl/inc/stdfloat

@@ -0,0 +1,36 @@
+// stdfloat standard header (core)
+
+// Copyright (c) Microsoft Corporation.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#pragma once
+#ifndef _STDFLOAT_
+#define _STDFLOAT_
+#include <yvals_core.h>
+#if _STL_COMPILER_PREPROCESSOR
+
+#if !_HAS_CXX23
+_EMIT_STL_WARNING(STL4038, "The contents of <stdfloat> are available only with C++23 or later.");
+#else // ^^^ !_HAS_CXX23 / _HAS_CXX23 vvv
+
+#pragma pack(push, _CRT_PACKING)
+#pragma warning(push, _STL_WARNING_LEVEL)
+#pragma warning(disable : _STL_DISABLED_WARNINGS)
+_STL_DISABLE_CLANG_WARNINGS
+#pragma push_macro("new")
+#undef new
+
+// We don't support any optional extended floating-point types, but we do need to provide an empty `namespace std`.
+// We don't need to `export` it for modules, as the other headers will implicitly do so (N4928 [module.interface]/2.1).
+_STD_BEGIN
+_STD_END
+
+#pragma pop_macro("new")
+_STL_RESTORE_CLANG_WARNINGS
+#pragma warning(pop)
+#pragma pack(pop)
+
+#endif // ^^^ _HAS_CXX23 ^^^
+
+#endif // _STL_COMPILER_PREPROCESSOR
+#endif // _STDFLOAT_

stl/inc/yvals_core.h

@@ -319,6 +319,8 @@
 // P1272R4 byteswap()
 // P1328R1 constexpr type_info::operator==()
 // P1425R4 Iterator Pair Constructors For stack And queue
+// P1467R9 Extended Floating-Point Types
+//     (only the <stdfloat> header; we don't support any optional extended floating-point types)
 // P1659R3 ranges::starts_with, ranges::ends_with
 // P1679R3 contains() For basic_string/basic_string_view
 // P1682R3 to_underlying() For Enumerations

stl/modules/std.ixx

@@ -101,6 +101,7 @@ export module std;
 #include <stack>
 #include <stacktrace>
 #include <stdexcept>
+#include <stdfloat>
 #include <stop_token>
 #include <streambuf>
 #include <string>

tests/std/include/test_header_units_and_modules.hpp

@@ -782,6 +782,12 @@ void test_stdexcept() {
     assert(caught_puppies);
 }
 
+void test_stdfloat() {
+    using namespace std;
+    puts("Testing <stdfloat>.");
+    // `namespace std` is available, so we're done.
+}
+
 void test_stop_token() {
     using namespace std;
     puts("Testing <stop_token>.");
@@ -1120,6 +1126,7 @@ void all_cpp_header_tests() {
     test_stack();
     test_stacktrace();
     test_stdexcept();
+    test_stdfloat();
     test_stop_token();
     test_streambuf();
     test_string();

tests/std/tests/Dev10_555491_complex_linker_errors/test.cpp

@@ -292,4 +292,10 @@ int main() {
     assert((proj(-inf) == complex<double>{inf, 0.0}));
 
     test_gh_2728();
+
+    // Also test N4928 [complex.numbers.general]/2:
+    // "Specializations of complex for cv-unqualified floating-point types are trivially-copyable literal types"
+    STATIC_ASSERT(is_trivially_copyable_v<complex<float>>);
+    STATIC_ASSERT(is_trivially_copyable_v<complex<double>>);
+    STATIC_ASSERT(is_trivially_copyable_v<complex<long double>>);
 }

tests/std/tests/P1502R1_standard_library_header_units/importable_cxx_library_headers.jsonc

@@ -65,6 +65,7 @@
     "stack",
     "stacktrace",
     "stdexcept",
+    "stdfloat",
     "stop_token",
     "streambuf",
     "string",

tests/std/tests/P1502R1_standard_library_header_units/test.cpp

@@ -71,6 +71,7 @@ import <sstream>;
 import <stack>;
 import <stacktrace>;
 import <stdexcept>;
+import <stdfloat>;
 import <stop_token>;
 import <streambuf>;
 import <string>;

tests/std/tests/include_each_header_alone_matrix.lst

@@ -70,6 +70,7 @@ PM_CL="/DMEOW_HEADER=stack"
 PM_CL="/DMEOW_HEADER=stacktrace"
 PM_CL="/DMEOW_HEADER=stdatomic.h"
 PM_CL="/DMEOW_HEADER=stdexcept"
+PM_CL="/DMEOW_HEADER=stdfloat"
 PM_CL="/DMEOW_HEADER=stop_token"
 PM_CL="/DMEOW_HEADER=streambuf"
 PM_CL="/DMEOW_HEADER=string"