Perhaps consider using __attribute__((cleanup()) on GCC?

[TheLoneWolfling]

GCC (& Clang) have a variable attribute that runs a function when a variable goes out of scope.

This allows for writing a with that handles return statements and such properly.

A quick example of the underlying concept:

#include "stdio.h"

void write_samples(const char *path, int numSamples, const float *samples)
{
    // Mild annoyance - cleanup takes a pointer to the variable.
    // Which you need to plumb through if the cleanup function takes it by value.
    void cleanup(FILE **f) {fclose(*f);}
    // nested functions are another GNUism. In C++11 or later you could use a lambda instead.
    FILE *fp __attribute__((cleanup(cleanup))) = fopen(path, "wb");
    fprintf(fp, "%d\n", numSamples);
    if (ferror(fp))
        return;
    for (int i = 0; i < numSamples; i++)
        fprintf(fp, "%f\n", samples[i]);
}

(In C++ replace the nested function with a lambda.)

In C++ this even handles exceptions sanely (read: runs the cleanup as part of exception handling).

[taeber]

Thank you @TheLoneWolfling for providing an example of the cleanup attribute. I had mentioned it along with MSVC's try-finally as common alternatives in the README, but I know examples are helpful.

I'm assuming you are coming from Hacker News. I'll leave this issue open in case other people want to comment.

Thanks again. Take care!