Macro _MSVC_STL_UPDATE

We've implemented the Standard's feature-test macros, which are the best way to determine whether a feature is supported by your current combination of compiler vendor, compiler version, library vendor, library version, and build settings. However, it can occasionally be useful to query the library version directly. We provide an implementation-specific macro _MSVC_STL_UPDATE defined in the STL's central internal header yvals_core.h; users should include <version> or any other Standard header to get this macro. This macro follows the year-month format of Standard feature-test macros, but isn't related to any of them. We simply intend to update the value of _MSVC_STL_UPDATE every month, so when a Visual Studio update ships, it captures a new value.

Here are the historical values of this macro, verified from actual installations of released (non-preview) Visual Studio updates:

MSVC Compiler _MSC_VER	MSVC Build Tools	Visual Studio	_MSVC_STL_UPDATE	Required Clang	Required CUDA	Notes
1944	14.44	VS 2022 17.14	202503L	Clang 19
1943	14.43	VS 2022 17.13	202411L	Clang 18
1942	14.42	VS 2022 17.12	202408L
1941	14.41	VS 2022 17.11	202405L		CUDA 12.4.0
1940	14.40	VS 2022 17.10	202402L	Clang 17		CUDA 12.4.0 began allowing _MSC_VER=1940
1939	14.39	VS 2022 17.9	202310L
1938	14.38	VS 2022 17.8	202308L
1937	14.37	VS 2022 17.7	202305L	Clang 16
1936	14.36	VS 2022 17.6	202302L
1935	14.35	VS 2022 17.5	202210L	Clang 15
1934	14.34	VS 2022 17.4	202208L	Clang 14	CUDA 11.6.0
1933	14.33	VS 2022 17.3	202205L
1932	14.32	VS 2022 17.2	202203L	Clang 13
1931	14.31	VS 2022 17.1	202111L
1930	14.30	VS 2022 17.0	202108L	Clang 12		CUDA 11.6.0 began allowing _MSC_VER=1930
1929	14.29	VS 2019 16.11.14	202105L			/std:c++20 complete
1929	14.29	VS 2019 16.11	202104L			Only #1929 in 16.11.0 and #2060 in 16.11.4
1929	14.29	VS 2019 16.10	202104L	Clang 11	CUDA 10.1 Update 2
1928	14.28	VS 2019 16.9	202011L
1928	14.28	VS 2019 16.8	202008L
1927	14.27	VS 2019 16.7	202005L	Clang 10
1926	14.26	VS 2019 16.6	202002L
1925	14.25	VS 2019 16.5	201912L	Clang 9
1924	14.24	VS 2019 16.4	201909L	Clang 8.0.1
1923	14.23	VS 2019 16.3	201906L
1922	14.22	VS 2019 16.2	201905L	Clang 8
1921	14.21	VS 2019 16.1	201903L
1920	14.20	VS 2019 16.0	201811L			CUDA 10.1 RTW began allowing _MSC_VER=1920
1916	14.16	VS 2017 15.9	201809L
1915	14.15	VS 2017 15.8	201806L
1914	14.14	VS 2017 15.7	201803
1913	14.13	VS 2017 15.6	201711
1912	14.12	VS 2017 15.5	201709
older	older	older	none			_MSVC_STL_UPDATE did not exist prior to VS 2017 15.5