Hi. Here a very typical clang6 fix.
Regards.
Index: patches/patch-src_SFML_Window_Unix_WindowImplX11_cpp =================================================================== RCS file: patches/patch-src_SFML_Window_Unix_WindowImplX11_cpp diff -N patches/patch-src_SFML_Window_Unix_WindowImplX11_cpp --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ patches/patch-src_SFML_Window_Unix_WindowImplX11_cpp 10 Apr 2018 17:54:02 -0000 @@ -0,0 +1,14 @@ +$OpenBSD$ + +Index: src/SFML/Window/Unix/WindowImplX11.cpp +--- src/SFML/Window/Unix/WindowImplX11.cpp.orig ++++ src/SFML/Window/Unix/WindowImplX11.cpp +@@ -1592,7 +1592,7 @@ void WindowImplX11::initialize() + m_window, + XNInputStyle, + XIMPreeditNothing | XIMStatusNothing, +- reinterpret_cast<void*>(NULL) ++ static_cast<void*>(NULL) + ); + } + else
