embed-function

A very tiny C++ wrapper for callable object without any heap memory or exception. It is used in the same way as std::function.

---

Basic Usage

• normal function

#include "embed_function.hpp"
#include <cstdio>

void print_num(int num) { printf("hello %d", num); }

int main()
{
    embed::function<void(int)> fn = print_num;
    fn(123);
    return 0;
}

• lambda function

#include "embed_function.hpp"
#include <iostream>

int main()
{
    embed::function<void()> fn = []() { std::cout << "hello world" << std::endl; };
    fn();
    return 0;
}

• callable object

#include "embed_function.hpp"
#include <iostream>
#include <string>

struct Test
{
    std::string str;
    void operator()() const
    {
        std::cout << this->str << std::endl;
    }
};

int main()
{
    Test t{"hello world"};
    embed::function<void(), sizeof(std::string)> fn = t;
    fn();
    return 0;
}

Use embed::make_function

• Normal function

#include "embed_function.hpp"
#include <cstdio>

void print_num(int num) { printf("hello %d", num); }

int main()
{
    // The type of fn is embed::function<void(int)>
    auto fn = embed::make_function(print_num);
    fn(123);
    return 0;
}

• lambda function

#include "embed_function.hpp"
#include <iostream>

int main()
{
    // The type of fn is embed::function<void()>
    auto fn = embed::make_function(
        []() { std::cout << "hello world" << std::endl; });
    fn();
    return 0;
}

• callable object

#include "embed_function.hpp"
#include <iostream>
#include <string>

struct Test
{
    std::string str;
    void operator()() const
    {
        std::cout << this->str << std::endl;
    }
};

int main()
{
    Test t{"hello world"};
    // The type of fn is embed::function<void()>
    auto fn = embed::make_function(t);
    fn();
    return 0;
}