start a transient .path, .socket, or .timer unit, that activates a .service unit when elapsing. The GNU Compiler Collection includes front ends for C, C++, Objective-C, Objective-C++, Fortran, Ada, Go, D, Modula-2, COBOL, Rust, and Algol 68 as well as libraries for these languages (libstdc++,...). GCC was originally written as