C++正则表达式校验某个字符串是否是合格的email

可以借助正则表达式校验某个字符串是否是合规的电子邮箱。对于邮箱的正则表达式有严格的模式，如：^[a-zA-Z0-9_+&*-]+(?:\\.[a-zA-Z0-9_+&*-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,7}$
对应的C++实现如下：
// EmailValidator.h

#ifndef EMAIL_VALIDATOR_H
#define EMAIL_VALIDATOR_H

#include <string>

// Email地址校验类
class EmailValidator
{
public:
	// 校验email是否是合法的email地址
	static bool isValidEmail(const std::string& email);
};

#endif	// EMAIL_VALIDATOR_H

// EmailValidator.cpp

#include "EmailValidator.h"
#include <regex>

namespace {
	const std::string EMAIL_PATTERN = "^[a-zA-Z0-9_+&*-]+(?:\\.[a-zA-Z0-9_+&*-]+)*" \
		"@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,7}$";
}

bool EmailValidator::isValidEmail(const std::string& email)
{
	std::regex pattern(EMAIL_PATTERN);
	// Tests whether a regular expression matches the entire target string.
	if (std::regex_match(email, pattern)) {
		return true;
	}
	return false;
}

//测试main.cpp

#include "EmailValidator.h"
#include <iostream>

using namespace std;

// C++11标准 STL正则表达式 验证电子邮件地址
// https://blog.csdn.net/kyfvc/article/details/41082025

int main(int argc, char* argv[])
{
	std::string emailAddress;

	// while (std::getline(cin, emailAddress))
	while (cin >> emailAddress)
	{
		if (EmailValidator::isValidEmail(emailAddress)) {
			std::cout << "您输入的电子邮件地址: " << emailAddress << " 合法" << std::endl;
		} else {
			std::cout << "您输入的电子邮件地址: " << emailAddress << " 不合法" << std::endl;
		}
	}


	return 0;
}

运行结果如下图所示：