Return Value Flow

A returned value can flow directly into a new object without requiring the caller to manage a separate temporary.

return_value_flow.cpp

#include <iostream>
#include <string>

std::string make_label(int count) {
    return "item" + std::to_string(count);
}

int main() {
    int count = ;

    std::string label = make_label(count);
    int size = static_cast<int>(label.size());

    std::cout << "label=" << label << std::endl;
    std::cout << "size=" << size << std::endl;
    return 0;
}

#include <iostream>
#include <string>

std::string make_label(int count) {
    return "item" + std::to_string(count);
}

int main() {
    int count = ;

    std::string label = make_label(count);
    int size = static_cast<int>(label.size());

    std::cout << "label=" << label << std::endl;
    std::cout << "size=" << size << std::endl;
    return 0;
}

#include <iostream>
#include <string>

std::string make_label(int count) {
    return "item" + std::to_string(count);
}

int main() {
    int count = ;

    std::string label = make_label(count);
    int size = static_cast<int>(label.size());

    std::cout << "label=" << label << std::endl;
    std::cout << "size=" << size << std::endl;
    return 0;
}

return value A function can create a value and return it to the caller.

prvalue A pure rvalue expression can initialize a named object at the call site.