Visual Studio - std::ftell performance issue - better example

main.cpp

#define _CRT_SECURE_NO_WARNINGS

#include <cstdio>

int main()
{
    // Search the first 32MiB for a Z character
    constexpr auto maxToRead = 32 * 1024 * 1024;

    auto f = std::fopen("test.dat", "rb");

    while (!std::feof(f) && (std::ftell(f) < maxToRead))
    {
        char c;
        if (std::fread(&c, 1, 1, f) && (c == 'Z'))
        {
            return 0;
        }
    }

    return 1;
}