Merge pull request kokkos#195 from JBludau/windows_h_include

Short explanation to windows.h problem
marcinwrobel1986 · Oct 21, 2022 · 1022476 · 1022476
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diff --git a/docs/source/usecases.rst b/docs/source/usecases.rst
@@ -13,3 +13,4 @@ Use Cases and Examples
    ./usecases/Tasking
    ./usecases/Kokkos-Fortran-Interoperability
    ./usecases/SoA-and-AoSoA-with-Cabana
+   ./usecases/WindowsHeader
diff --git a/docs/source/usecases/WindowsHeader.md b/docs/source/usecases/WindowsHeader.md
@@ -0,0 +1,7 @@
+# Kokkos and `Windows.h`
+
+When using Kokkos on Windows a program or library might include `windows.h`. This is problematic as this header defines two macros with the names `min` and `max` unless `NOMINMAX` is defined previously.
+The preprocessor replaces strings in the source code with the macros yielding an uninterpretable result and thus compilation fails.
+Therefore, the header `Kokkos_Core.hpp` is protected against these macros, meaning they are undefined at the beginning and redefined at the end of the header file.
+Even though definitions inside `Kokkos_Core.hpp` are protected against the macros, code outside is not.
+Thus, it is on the user to deal with the macros being defined, either by defining `-DNOMINMAX` or `/DNOMINMAX` in the compile line (preferred) or by putting `()` around names that contain `min` or `max`.