Compile errors when using VS 2015

[NickWaanders]

Hi,

I am trying to compile bgfx using Visual Studio 2015, and I am getting the following errors:

1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(189): error C3250: 'add': declaration is not allowed in 'constexpr' function body (compiling source file ..\..\..\..\bx\src\easing.cpp)
1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(189): error C3249: illegal statement or sub-expression for 'constexpr' function (compiling source file ..\..\..\..\bx\src\easing.cpp)
1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(190): error C3250: 'lt': declaration is not allowed in 'constexpr' function body (compiling source file ..\..\..\..\bx\src\easing.cpp)
1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(190): error C3249: illegal statement or sub-expression for 'constexpr' function (compiling source file ..\..\..\..\bx\src\easing.cpp)
1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(191): error C3250: 'result': declaration is not allowed in 'constexpr' function body (compiling source file ..\..\..\..\bx\src\easing.cpp)
1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(189): error C3250: 'add': declaration is not allowed in 'constexpr' function body (compiling source file ..\..\..\..\bx\src\bx.cpp)
1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(191): error C3249: illegal statement or sub-expression for 'constexpr' function (compiling source file ..\..\..\..\bx\src\easing.cpp)
1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(189): error C3249: illegal statement or sub-expression for 'constexpr' function (compiling source file ..\..\..\..\bx\src\bx.cpp)
1>c:\bgfx\bx\include\bx\inline/uint32_t.inl(190): error C3250: 'lt': declaration is not allowed in 'constexpr' function body (compiling source file ..\..\..\..\bx\src\bx.cpp)

Is there anything I am doing wrong?

Cheers,
Nick

[mlabbe]

I'm getting these as well when building master branch of bgfx & bx. They go away when using vs2017.

Is there a workaround for earlier vs compilers?

[x1nixmzeng]

The main project page explains the supported compiler is "VS2017 and above".

Either target a later version of C++ or upgrade your IDE

[NickWaanders]

Ah, you are correct.

I was looking at this page (which is linked from the main github page) https://bkaradzic.github.io/bgfx/overview.html which lists vs2015 under the supported compilers.

[bkaradzic]

I just need to update docs. VS2017 supports C++14 constexpr features I use.

One thing you can do is to remove constexpr from BX_CONSTEXPR_FUNC and it will compile with VS2015 or below.