Deferpp (Defer++) is Go-like DEFER construction for C++ (execute code on scope exit)

Simple, lightweight, header-only, quick and portable Go-like DEFER construction for C++11 and above to do automatic resource cleanup once scope is exited. The header deferpp.h is the only file needed to add DEFER macro for automatic resounce cleanup. DEFER is implemented in standard C++11 (but without involving any "heavywaight" stuff like std::function and without any dependencies at all!).

Sample sage:

{
    auto resource = AcquireSomeResource(parameters_here)
    DEFER{ FreeeThatResource(resource); };
    
    ... //work with that resource
}
//Note: code after DEFER is called when leaving scope due to any reason
//      (one can reach scope end, issue return/break/continue or throw
//       some exception, there is a guarantee such deferred code is called)

Intended to be quick alternative for resource management and serves as a fast scope guard instead of coding RAII classes by hand. Use DEFER construction to ensure cleanup code is called automatically once {} scope is exited. Those ones being familiar with defer keyword in golang can now use DEFER macro in C++ and one does not need to write RAII wrapper class manually for every unique kind of resource usage. Header-only library (single header deferpp.h). No installation required, no build needed, just copy deferpp.h header file to any location in wour project you like :)

More complex demo:

#include "deferpp.h"
#include <iostream>

int main() {
    int i = 0;
    std::cout << "Enter application, i = " << i << std::endl;
    {
        std::cout << "After enter scope, i = " << i << std::endl;

        DEFER {
            ++i;
            std::cout << "Lambda called (apply side effect), i = " << i << std::endl;
        };

        std::cout << "Before exit scope, i = " << i << std::endl;
    }
    std::cout << "Exit application, i = " << i << std::endl;
    return 0;
}

Expected output is:

    Enter application, i = 0
    After enter scope, i = 0
    Before exit scope, i = 0
    Lambda called (apply side effect), i = 1
    Exit application, i = 1

Using DEFER macro allows easy debugging of your cleanup code in any IDE, just place debug break inside {} ))