GSL is a Guidelines Support Library for C++ that provides a set of types and functions designed to implement the C++ Core Guidelines. It functions as a framework for improving code safety and portability across different platforms.
The library provides a contract-based programming model to verify program invariants through precondition and postcondition assertions. It includes specialized wrappers for null-pointer safety and bounds-checked memory views to prevent buffer overflows and invalid memory access.
The project also covers safe integer conversion to prevent data truncation and provides utilities for managing zero-terminated strings with various character encodings. Additionally, it includes mechanisms for resource management to ensure cleanup functions execute during object destruction.