lambda size

lambda_size.cpp

#include <cstdio>

int main() {

    int x = 23;
    int y = 45;

    auto l1 = [] () {
        std::printf("l1\n");
    };

    auto l2 = [&x] () {
        std::printf("l2 %d\n", x);
    };

    auto l3 = [&y] () {
        std::printf("l3 %d\n", y);
    };

    auto l4 = [&] () {
        std::printf("l4 %d\n", y);
    };

    auto l5 = [&] () {
        if (false)
        {
            std::printf("l5 %d\n", y);
        }
        else
        {
            std::printf("l5\n");
        }
    };

    std::printf("l1 size: %lu\n", sizeof(l1));
    std::printf("l2 size: %lu\n", sizeof(l3));
    std::printf("l3 size: %lu\n", sizeof(l3));
    std::printf("l4 size: %lu\n", sizeof(l4));
    std::printf("l5 size: %lu\n", sizeof(l5));

    l1();
    l2();
    l3();
    l4();
    l5();

    return 0;
}

/*
l1 size: 1                                                                                                                     
l2 size: 8                                                                                                                     
l3 size: 8                                                                                                                     
l4 size: 8                                                                                                                     
l5 size: 8                                                                                                                     
l1                                                                                                                             
l2 23                                                                                                                          
l3 45                                                                                                                          
l4 45                                                                                                                          
l5      
*/

https://gcc.godbolt.org/z/lXjBbY