stdruntimeerrorError

The `std::runtime_error` is a standard exception class defined in the C++ Standard Library within the `<stdexcept>` header. It is part of the hierarchy of standard exceptions introduced to provide a consistent way of handling runtime errors in C++ programs. This class is derived from the base class `std::exception`, which serves as the foundation for all standard exceptions in C++.

`std::runtime_error` is used to signal errors that occur during the normal execution of a program, as opposed to errors that might be detected at compile time or those related to resource allocation (like `std::bad_alloc`). Unlike exceptions that indicate logical errors (e.g., `std::logic_error`), `std::runtime_error` is intended for unexpected conditions that arise during runtime, such as invalid arguments passed to a function or failures in external operations like file I/O.

When constructing a `std::runtime_error`, a descriptive error message is provided as an argument to the constructor. This message can later be accessed using the `what()` member function, which returns a `const char*` string. For example, `std::runtime_error("File not found")` creates an exception with the message "File not found," which can be caught and handled elsewhere in the program.

The use of `std::runtime_error` promotes better error handling practices by separating error conditions from the core logic of a program. It allows developers to write more robust code by explicitly declaring where and how errors might occur, making the code easier to debug and maintain. While `std::runtime_error` is flexible, it is generally recommended to use more specific exception types when available to provide clearer error context.