[libc++][format] define __cpp_lib_format. #98275
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In order to define the format __cpp_lib_format to its initial value (201907) these papers need to be completed: - P0645R10 Text Formatting - P1652R1 Printf corner cases in std::format - 1361R2 Integration of chrono with text formatting The first two have been implemented for a while the latter is almost done. The next value (202106) requires: - P2216R3 std::format improvements which has been implemented The next value (202110) requires: - P2418R2 Add support for std::generator-like types to std::format - P2372R3 Fixing locale handling in chrono formatters The first one has been implemented for a while the latter is almost done. The latter paper is a DR against 1361R2 and both are implemented at the same time. We've had user feedback that the missing of the __cpp_lib_format makes their lives harder (llvm#77773). The missing papers 1361R2 and P2372R3 are very close to completion and might completed before LLVM-19, but it will be a close call. This has been discussed in the monthly libc++ meeting and we decided to set the __cpp_lib_format so it will be set in LLVM-19. Based on the discussion and the implementation status the __cpp_lib_format is set to 202110
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@llvm/pr-subscribers-libcxx Author: Mark de Wever (mordante) ChangesIn order to define the format __cpp_lib_format to its initial value (201907) these papers need to be completed:
The next value (202106) requires:
The next value (202110) requires:
We've had user feedback that the missing of the __cpp_lib_format makes their lives harder (#77773). The missing papers 1361R2 and P2372R3 are very close to completion and might completed before LLVM-19, but it will be a close call. This has been discussed in the monthly libc++ meeting and we decided to set the __cpp_lib_format so it will be set in LLVM-19. Based on the discussion and the implementation status the __cpp_lib_format is set to 202110 Full diff: https://github.com/llvm/llvm-project/pull/98275.diff 5 Files Affected:
diff --git a/libcxx/docs/FeatureTestMacroTable.rst b/libcxx/docs/FeatureTestMacroTable.rst
index 2a34aa4fe55cc..7cd20acc6ff4a 100644
--- a/libcxx/docs/FeatureTestMacroTable.rst
+++ b/libcxx/docs/FeatureTestMacroTable.rst
@@ -234,7 +234,7 @@ Status
---------------------------------------------------------- -----------------
``__cpp_lib_execution`` *unimplemented*
---------------------------------------------------------- -----------------
- ``__cpp_lib_format`` *unimplemented*
+ ``__cpp_lib_format`` ``202110L``
---------------------------------------------------------- -----------------
``__cpp_lib_format_uchar`` ``202311L``
---------------------------------------------------------- -----------------
diff --git a/libcxx/include/version b/libcxx/include/version
index 21231a4d4b0fc..1f66bce40df8a 100644
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -101,7 +101,7 @@ __cpp_lib_execution 201902L <execution>
201603L // C++17
__cpp_lib_expected 202211L <expected>
__cpp_lib_filesystem 201703L <filesystem>
-__cpp_lib_format 202106L <format>
+__cpp_lib_format 202110L <format>
__cpp_lib_format_path 202403L <filesystem>
__cpp_lib_format_ranges 202207L <format>
__cpp_lib_format_uchar 202311L <format>
@@ -403,7 +403,7 @@ __cpp_lib_void_t 201411L <type_traits>
# define __cpp_lib_erase_if 202002L
# undef __cpp_lib_execution
// # define __cpp_lib_execution 201902L
-// # define __cpp_lib_format 202106L
+# define __cpp_lib_format 202110L
# define __cpp_lib_format_uchar 202311L
# define __cpp_lib_generic_unordered_lookup 201811L
# define __cpp_lib_int_pow2 202002L
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/format.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/format.version.compile.pass.cpp
index aa7b2f4286827..7bb2fa399b094 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/format.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/format.version.compile.pass.cpp
@@ -16,7 +16,7 @@
// Test the feature test macros defined by <format>
/* Constant Value
- __cpp_lib_format 202106L [C++20]
+ __cpp_lib_format 202110L [C++20]
__cpp_lib_format_ranges 202207L [C++23]
__cpp_lib_format_uchar 202311L [C++20]
*/
@@ -68,17 +68,11 @@
#elif TEST_STD_VER == 20
-# if !defined(_LIBCPP_VERSION)
-# ifndef __cpp_lib_format
-# error "__cpp_lib_format should be defined in c++20"
-# endif
-# if __cpp_lib_format != 202106L
-# error "__cpp_lib_format should have the value 202106L in c++20"
-# endif
-# else // _LIBCPP_VERSION
-# ifdef __cpp_lib_format
-# error "__cpp_lib_format should not be defined because it is unimplemented in libc++!"
-# endif
+# ifndef __cpp_lib_format
+# error "__cpp_lib_format should be defined in c++20"
+# endif
+# if __cpp_lib_format != 202110L
+# error "__cpp_lib_format should have the value 202110L in c++20"
# endif
# ifdef __cpp_lib_format_ranges
@@ -94,17 +88,11 @@
#elif TEST_STD_VER == 23
-# if !defined(_LIBCPP_VERSION)
-# ifndef __cpp_lib_format
-# error "__cpp_lib_format should be defined in c++23"
-# endif
-# if __cpp_lib_format != 202106L
-# error "__cpp_lib_format should have the value 202106L in c++23"
-# endif
-# else // _LIBCPP_VERSION
-# ifdef __cpp_lib_format
-# error "__cpp_lib_format should not be defined because it is unimplemented in libc++!"
-# endif
+# ifndef __cpp_lib_format
+# error "__cpp_lib_format should be defined in c++23"
+# endif
+# if __cpp_lib_format != 202110L
+# error "__cpp_lib_format should have the value 202110L in c++23"
# endif
# ifndef __cpp_lib_format_ranges
@@ -123,17 +111,11 @@
#elif TEST_STD_VER > 23
-# if !defined(_LIBCPP_VERSION)
-# ifndef __cpp_lib_format
-# error "__cpp_lib_format should be defined in c++26"
-# endif
-# if __cpp_lib_format != 202106L
-# error "__cpp_lib_format should have the value 202106L in c++26"
-# endif
-# else // _LIBCPP_VERSION
-# ifdef __cpp_lib_format
-# error "__cpp_lib_format should not be defined because it is unimplemented in libc++!"
-# endif
+# ifndef __cpp_lib_format
+# error "__cpp_lib_format should be defined in c++26"
+# endif
+# if __cpp_lib_format != 202110L
+# error "__cpp_lib_format should have the value 202110L in c++26"
# endif
# ifndef __cpp_lib_format_ranges
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
index c0ffd78ebe3b1..aa5ff80afb56a 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
@@ -88,7 +88,7 @@
201902L [C++20]
__cpp_lib_expected 202211L [C++23]
__cpp_lib_filesystem 201703L [C++17]
- __cpp_lib_format 202106L [C++20]
+ __cpp_lib_format 202110L [C++20]
__cpp_lib_format_path 202403L [C++26]
__cpp_lib_format_ranges 202207L [C++23]
__cpp_lib_format_uchar 202311L [C++20]
@@ -3618,17 +3618,11 @@
# endif
# endif
-# if !defined(_LIBCPP_VERSION)
-# ifndef __cpp_lib_format
-# error "__cpp_lib_format should be defined in c++20"
-# endif
-# if __cpp_lib_format != 202106L
-# error "__cpp_lib_format should have the value 202106L in c++20"
-# endif
-# else // _LIBCPP_VERSION
-# ifdef __cpp_lib_format
-# error "__cpp_lib_format should not be defined because it is unimplemented in libc++!"
-# endif
+# ifndef __cpp_lib_format
+# error "__cpp_lib_format should be defined in c++20"
+# endif
+# if __cpp_lib_format != 202110L
+# error "__cpp_lib_format should have the value 202110L in c++20"
# endif
# ifdef __cpp_lib_format_path
@@ -5063,17 +5057,11 @@
# endif
# endif
-# if !defined(_LIBCPP_VERSION)
-# ifndef __cpp_lib_format
-# error "__cpp_lib_format should be defined in c++23"
-# endif
-# if __cpp_lib_format != 202106L
-# error "__cpp_lib_format should have the value 202106L in c++23"
-# endif
-# else // _LIBCPP_VERSION
-# ifdef __cpp_lib_format
-# error "__cpp_lib_format should not be defined because it is unimplemented in libc++!"
-# endif
+# ifndef __cpp_lib_format
+# error "__cpp_lib_format should be defined in c++23"
+# endif
+# if __cpp_lib_format != 202110L
+# error "__cpp_lib_format should have the value 202110L in c++23"
# endif
# ifdef __cpp_lib_format_path
@@ -6748,17 +6736,11 @@
# endif
# endif
-# if !defined(_LIBCPP_VERSION)
-# ifndef __cpp_lib_format
-# error "__cpp_lib_format should be defined in c++26"
-# endif
-# if __cpp_lib_format != 202106L
-# error "__cpp_lib_format should have the value 202106L in c++26"
-# endif
-# else // _LIBCPP_VERSION
-# ifdef __cpp_lib_format
-# error "__cpp_lib_format should not be defined because it is unimplemented in libc++!"
-# endif
+# ifndef __cpp_lib_format
+# error "__cpp_lib_format should be defined in c++26"
+# endif
+# if __cpp_lib_format != 202110L
+# error "__cpp_lib_format should have the value 202110L in c++26"
# endif
# if !defined(_LIBCPP_VERSION)
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index e92b6613b11a8..7bc11aa401829 100755
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -507,10 +507,7 @@ def add_version_header(tc):
{
"name": "__cpp_lib_format",
"values": {
- # "c++20": 201907 Not implemented P1361R2 Integration of chrono with text formatting
- # "c++20": 202106 Fully implemented
- # "c++20": 202110 Not implemented P2372R3 Fixing locale handling in chrono formatters
- "c++20": 202106,
+ "c++20": 202110,
# "c++23": 202207, Not implemented P2419R2 Clarify handling of encodings in localized formatting of chrono types
# "c++26": 202306, P2637R3 Member Visit (implemented)
# "c++26": 202311, P2918R2 Runtime format strings II (implemented)
@@ -520,7 +517,6 @@ def add_version_header(tc):
# 202305 P2757R3 Type-checking format args
# 202306 P2637R3 Member Visit
"headers": ["format"],
- "unimplemented": True,
},
{
"name": "__cpp_lib_format_path",
|
ldionne
approved these changes
Jul 10, 2024
aaryanshukla
pushed a commit
to aaryanshukla/llvm-project
that referenced
this pull request
Jul 14, 2024
In order to define the format __cpp_lib_format to its initial value (201907) these papers need to be completed: - P0645R10 Text Formatting - P1652R1 Printf corner cases in std::format - 1361R2 Integration of chrono with text formatting The first two have been implemented for a while the latter is almost done. The next value (202106) requires: - P2216R3 std::format improvements which has been implemented The next value (202110) requires: - P2418R2 Add support for std::generator-like types to std::format - P2372R3 Fixing locale handling in chrono formatters The first one has been implemented for a while the latter is almost done. The latter paper is a DR against 1361R2 and both are implemented at the same time. We've had user feedback that the missing of the __cpp_lib_format makes their lives harder (llvm#77773). The missing papers 1361R2 and P2372R3 are very close to completion and might completed before LLVM-19, but it will be a close call. This has been discussed in the monthly libc++ meeting and we decided to set the __cpp_lib_format so it will be set in LLVM-19. Based on the discussion and the implementation status the __cpp_lib_format is set to 202110. Fixes llvm#77773
mordante
pushed a commit
that referenced
this pull request
Aug 4, 2024
Now that #98275 has been merged, the footnote for P0645 has become outdated. This updates the status information.
ldionne
pushed a commit
that referenced
this pull request
Jul 14, 2025
In #125921, the changes requested by P2372R3 were completed and tested together with corresponding `chrono` types. But that PR didn't mention P2372R3. The `__cpp_lib_format` FTM was even bumped by an earlier PR #98275. This PR confirms that P2372R3 was completed in LLVM 21 (together with P1361R2). Closes #100043
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In order to define the format __cpp_lib_format to its initial value (201907) these papers need to be completed:
The next value (202106) requires:
The next value (202110) requires:
We've had user feedback that the missing of the __cpp_lib_format makes their lives harder (#77773). The missing papers 1361R2 and P2372R3 are very close to completion and might completed before LLVM-19, but it will be a close call. This has been discussed in the monthly libc++ meeting and we decided to set the __cpp_lib_format so it will be set in LLVM-19.
Based on the discussion and the implementation status the __cpp_lib_format is set to 202110.
Fixes #77773