Compiler Support

• GCC >= 14
• Clang >= 17
• Microsoft Visual C++

C++ standard library support

• GCC libstdc++
• LLVM libc++
• MSVC STL

Architecture Support

• alpha
• i686
• x86_64
• arm
• aarch64
• riscv
• riscv64
• powerpc64
• wasm32-wasi
• mips-abi32
• mips-abin32
• mips-abi64
• avr
• ia64
• loongarch64
• xtensa-esp32
• All other architectures should work, they just aren't tested due to time not being infinite.

Platform Support

• Windows 10/12
• Windows Server 2019
• Linux
• BSD platforms (Including FreeBSD, NetBSD, OpenBSD)
• Apple Darwin (MacOS)
• Apple IOS
• Microsoft DOS
• FreeDOS
• Barebone (No any operating system.)
• Cygwin/MSYS2
• Android
• Wine
• Wine GCC
• ReactOS
• Windows Runtime
• Nintendo DS (devkitPro)
• Webassembly
• Managarm
• Vinix
• limine Bootloader
• AVR
• Banana
• LemonOS
• LLVM raw_fd_ostream
• Windows Kernel Driver
• Linux Kernel Module
• wasm2lua (Compile fast_io to Lua!)
• Intel PinTool (Dynamic Instrumentation)
• Any other platform (if you want me to support it, tell me, including your own OS)

Kernel Driver Support

• Windows NT kernel Driver
• Linux kernel Module

Legacy Windows Version Support

You need define _WIN32_WINNT and _WIN32_WINDOWS version by yourself.

On Windows 95 or 95 Plus! you can enable -O3 but not -Ofast. You'll also need msvcrt.dll.

• Windows 95
• Windows 95 Plus!
• Windows Nashville
• Microsoft Memphis
• Windows 98 FE
• Windows 98 SE
• Windows ME
• Microsoft Neptune
• Windows NT
• Windows Odyssey
• Windows 2000
• Windows Whistler
• Windows XP
• Windows Server 2003
• Windows Longhorn
• Windows Vista
• Windows Server 2008
• Windows Vienna
• Windows 7
• Windows 8
• Windows 8.1
• Windows Home Server 2011
• Windows Server 2012
• Windows Server 2016
• Windows 11. Windows 11 was a significant mistake.

Legacy Windows Version Support with DJGPP toolchain

• Windows 1.0
• Windows 2.0
• Windows 3.0
• Windows 3.1
• Microsoft Chicago
• Windows 95
• Windows 95 Plus!
• Microsoft Memphis
• Windows 98 FE
• Windows 98 SE
• Windows ME

Supported libc FILE* hacks platforms

• glibc
• MSVCRT
• Universal CRT
• Universal CRT with MSVC debugging
• Wine's MSVCRT
• Wine's UCRT 9.11+

See wine bug PR53960

• ReactOS MSVCRT
• ReactOS UCRT
• BSD libc/Apple Darwin
• MUSL libc
• DJGPP
• Newlib
• Bionic(Android)
• uclibc-ng
• wasi libc
• mlibc (this is a new libc which still contains a lot of bugs currently)
• avrlibc
• picolibc
• SerenityOS libc (untested)
• LLVM libc (untested)

Supported C++ standard library std::streambuf/std::filebuf hacks platforms

• GCC libstdc++
• LLVM libc++
• MSVC STL

Remote Debugger Support

• WinDbg
• Visual Studio Debugger
• DbgViewer
• Android ADB

Special Support

• LLVM Address Sanitizer
• Full freestanding support (which means we do not have any headers besides freestanding headers. Tested with GCC's --disable-hosted-libstdcxx without any libc, including newlib)
• Pintool support