蓝桥ROS机器人之现代C++学习笔记3.1 Lambda 表达式

Posted 2022-04-07 zhangrelay

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蓝桥ROS机器人之现代C++学习笔记支持C++17（已完成）_zhangrelay的博客-CSDN博客

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基础

1. 值捕获

2. 引用捕获

3. 隐式捕获

4. 表达式捕获

泛型 Lambda

#include <iostream>
#include <memory>  // std::make_unique
#include <utility> // std::move

void lambda_value_capture() 
    int value = 1;
    auto copy_value = [value] 
        return value;
    ;
    value = 100;
    auto stored_value = copy_value();
    std::cout << "stored_value = " << stored_value << std::endl;
    // At this moment, stored_value == 1, and value == 100.
    // Because copy_value has copied when its was created.


void lambda_reference_capture() 
    int value = 1;
    auto copy_value = [&value] 
        return value;
    ;
    value = 100;
    auto stored_value = copy_value();
    std::cout << "stored_value = " << stored_value << std::endl;
    // At this moment, stored_value == 100, value == 100.
    // Because copy_value stores reference


void lambda_expression_capture() 
    auto important = std::make_unique<int>(1);
    auto add = [v1 = 1, v2 = std::move(important)](int x, int y) -> int 
        return x+y+v1+(*v2);
    ;
    std::cout << add(3,4) << std::endl;


void lambda_generic() 
    auto generic = [](auto x, auto y) 
        return x+y;
    ;
    
    std::cout << generic(1, 2) << std::endl;
    std::cout << generic(1.1, 2.2) << std::endl;


int main() 
    lambda_value_capture();
    lambda_reference_capture();
    lambda_expression_capture();
    lambda_generic();
    return 0;

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