is string.substr presnt in c++11 code example

Example 1: find substring in string c++

std::string parentstring = "Hello Agnosticdev, I love Tutorials";
std::string substring = "Agnosticdev";
auto index = parentstring.find(substring);

Example 2: find in string c++

size_t find (const string& str, size_t pos = 0) const;