windef.h include via windows.h include causes issue with "near" and "far" names

[nvibd]

In our application related to 3D geometry, we use near and far names. Recently, we started using libcu++ and more specifically <cuda/std/atomic>. However, this causes issues as there is an indirect inclusion of "windef.h", which #defines "near" and "far" to nothing.

There are some possible workarounds, including adding #undefs for "near" and "far" after every libcu++ include, or renaming all conflicting variables.

Still, it would be preferable if libcu++ would somehow avoid or prevent these extra macro definitions coming from "windows.h".

[nvibd]

Here's a minimal example that causes compilation errors. Save as .cu or .cpp file, compile with nvcc.exe or cl.exe with the libcu++ includes.

#include <cuda/std/atomic>

struct A {
  float near;
  float far;
};

int main() { }

[nvibd]

The libcu++ version is the one included with CUDA 11.2.

cl.exe version:
Microsoft (R) C/C++ Optimizing Compiler Version 19.28.29336 for x64
nvcc.exe version:
Cuda compilation tools, release 11.2, V11.2.67

[miscco]

Unfortunately there is nothing we can do here.

[nvibd]

Would #undefs for near and far after "windef.h" includes inside libcu++ not be a workable fix?

[miscco]

We cannot #undef macros from a system header.

While at the moment the macro might be useless it could get some meaning in the future leading to havoc