如何在IF语句中搜索顶部括号？

if_statement = "if (condition) {"
index = if_statement.find("(")

let if_statement = "if (condition) {";
let index = if_statement.indexOf("(");

String if_statement = "if (condition) {";
int index = if_statement.indexOf("(");

#include<string>
#include<algorithm>

std::string if_statement = "if (condition) {";
int index = if_statement.find("(");

$if_statement = "if (condition) {";
$index = strpos($if_statement, "(");