Translation Unit

Definitions

1. The fundamental unit of compilation in C and C++: a single source file after the preprocessor has expanded all #include directives, macros, and conditional compilation — producing one complete input that the compiler processes into an object file.

   In plain English: A single source code file with all its included files merged together, ready for the compiler to process as one piece.

   Example: "Each .cpp file plus everything it #includes forms one translation unit — that's why you get linker errors when a symbol is defined in two TUs."

Related Terms

• Binary
• Build System
• Static Binary
• Static Dispatch
• Static Library
• Static Linking
• Type Punning
• Undefined Behavior