Remove leading and trailing whitespace in C++

To remove leading and trailing whitespaces from a string in C++, you can use the std::trim function from the header. Here's an example:

#include 
#include 
int main() {

    std::string str = "   hello world!    ";

    std::string trimmed_str = std::trim(str);

    std::cout << trimmed_str << std::endl; // Output: "hello world!"

    return 0;

}

In this example, we first define a string str that contains leading and trailing spaces. Then we use std::trim to remove these spaces and store the result in a new string trimmed_str. Finally, we print the trimmed string using std::cout. The output should be "hello world!" with the leading and trailing spaces removed.