Error:
expected unqualified-id before '(' token
 int fmt::BufferedFile::fileno() const {

This is an issue with Android NDK and mingw32.

https://github.com/Gachapen/cppformat/commit/c2ffa146841535080a3483471fd9eec77c119c36

to version https://github.com/cppformat/cppformat/commit/7ee287d3d9e340737f3ad66292e7bc60a53b3053

Silence some performance warnings in Visual Studio

Older Visual Studio versions are not shipped with stdint.h

in custom stream buffer implementation:

* basic_formatbuf -> internal::FormatBuf
* remove unused Traits template argument