std::basic_...:operator[](3)

okay so welcome to std::basic_...:operator[](3) from the C++ Standard Libary manual — this is the page for std::basic_string_view::operator[], and bestie, it's giving “tiny function, big main-character energy” ✨

🌸 NAME 🌸

std::basic_string_view::operator[] — yep, literally std::basic_string_view::operator[] 💅

🦋 Synopsis 🦋

constexpr const_reference operator[]( size_type pos ) const;  (since C++17)

Returns a const reference to the character at the specified location pos. Since C++17, no cap 🫶

⚠️ No bounds checking is performed: the behavior is undefined if pos >= size(). Like, not “oopsie” undefined — actual undefined behavior. Do not play with her 💀

💖 Parameters 💖

• pos — position of the character to return

👑 Return value 👑

Const reference to the requested character. Periodt.

💀 Exceptions 💀

Does not throw. She’s chill like that.

⚡ Complexity ⚡

Constant.

🌸 Notes 🌸

Unlike std::basic_string::operator[], std::basic_string_view::operator[](size()) has undefined behavior instead of returning CharT(). This is the messy little difference, iykyk 😭

🎀 Example 🎀

// Run this code

#include <iostream>
#include <string_view>

int main()
{
    std::string str = "Exemplar";
    std::string_view v = str;
    std::cout << v[2] << '\n';
//  v[2] = 'y'; // Error: cannot modify through a string view
    str[2] = 'y';
    std::cout << v[2] << '\n';
}

Output:

e
y

🌈 See also 🌈

• at — accesses the specified character with bounds checking (public member function)
• operator[] — accesses the specified character (public member function of std::basic_string<CharT,Traits,Allocator>)

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mwah 💋 this iconic little page came from http://cppreference.com, dated 2024.06.10 — catch you in the next manpage, bestie 🫶💖