`<xiosbase>`/`<random>`: error: out-of-line definition of `constexpr` static data member is redundant in C++17 and is deprecated `[-Werror,-Wdeprecated]`

[tiagomacarios]

When compiling with clang with -Wdeprecated on the build will emit:

lib\native\include\random(1454,45): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\random(1457,45): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\random(800,53): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\random(803,53): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(101,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(103,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(105,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(107,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(109,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(111,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(113,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(115,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(117,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(119,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(121,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(124,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(127,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(129,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(131,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(133,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(135,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(138,55): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(140,55): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(142,55): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(144,55): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(147,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(149,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(151,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(153,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(155,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(157,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(159,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(161,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(164,55): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(166,55): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(168,55): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(95,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(97,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]
lib\native\include\xiosbase(99,56): error: out-of-line definition of constexpr static data member is redundant in C++17 and is deprecated [-Werror,-Wdeprecated]

Assuming C++14 (or earlier) is still supported. I see 2 ways of fixing this:
1 - bulk suppressing -Wdeprecated by adding an entry to _STL_DISABLE_CLANG_WARNINGS
2 - Wrapping the offending code in #if _STL_LANG < 201703L

[frederick-vs-ja]

As said in #3006 (comment), perhaps it's possible to remove the out-of-class definitions even in C++14 mode, since MSVC and Clang seemly support such an extension.

---

Oh, the version of VS reported in this issue is probably VS 2022 17.2, and such out-of-class definitions in <random> have been removed in that PR (included in VS 2022 17.4).