What consequences may occur if an exception is thrown in a function declared as noexcept?

If an exception is thrown in a function declared as noexcept, it will call the std::terminate() function, which usually terminates the program abnormally. This is because noexcept guarantees that the function will not throw exceptions, and violating this contract is considered a critical error. Therefore, all exceptions inside noexcept functions should be carefully handled to prevent them from escaping.