SafeCast

SafeCast is a simple C++ header only library checking integer conversion.

Installation

Download the safecast.h and include it in your project.

Or consume it as a CMake target:

include(FetchContent)
FetchContent_Declare(SafeCast GIT_REPOSITORY https://github.com/Hexik/safe_cast.git GIT_TAG master)
FetchContent_MakeAvailable(SafeCast)

target_link_libraries(myapp PRIVATE SafeCast::SafeCast)

After cmake --install, find_package(SafeCast REQUIRED) provides the same SafeCast::SafeCast target.

Usage

Replace static_cast<> by safe_cast<> and insert safecast<> to places that indicate a warning -Wconversion. Use C++14 standard at least.

#include "safecast.h"

int32_t i32 = std::numeric_limits<int16_t>::max();

int16_t i16 = safe_cast<int16_t>( i32 ); // fits, no exception

try {
    i16 = safe_cast<int16_t>( i32 + 1 ); // throws
} catch( const SafeCastException& e ) {
    std::cerr << e.what() << '\n'; // signed to signed 32768 limit: 32767
}

Enums are resolved to their underlying type on both sides, so a negative enumerator cannot silently slip into a narrower type.

Exceptions are used for overflow signaling, it is possible to use assert, logging, ... Define NO_SAFECAST to compile all checks away, safe_cast<> then degrades to static_cast<>.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

• MIT license
• Copyright 2014-2026 (c) Miroslav Fontan