Class Exception

include/common.hpp:213–223

An exception explicitly thrown by Rack or a Rack plugin. Can be subclassed to throw/catch specific custom exceptions. */

Can be subclassed to throw/catch specific custom exceptions.
*/
struct Exception : std::exception {
	std::string msg;

	// Attribute index 1 refers to `Exception*` argument so use 2.
	__attribute__((format(printf, 2, 3)))
	Exception(const char* format, ...);
	Exception(const std::string& msg) : msg(msg) {}
	const char* what() const noexcept override {
		return msg.c_str();
	}
};


/** Given a std::map `c`, returns the value of the given key, or returns `def` if the key doesn't exist.