[lex.separate] (original) (raw)

5 Lexical conventions [lex]

5.1 Separate translation [lex.separate]

The text of the program is kept in units calledsource files in this document.

A source file together with all the and source files included via the preprocessing directive #include, less any source lines skipped by any of the conditional inclusion ([cpp.cond]) preprocessing directives, as modified by the implementation-defined behavior of any conditionally-supported-directives ([cpp.pre]) and pragmas ([cpp.pragma]), if any, is called a preprocessing translation unit.

[Note 1:

A C++ program need not all be translated at the same time.

— _end note_]

[Note 2:

Previously translated translation units and instantiation units can be preserved individually or in libraries.

The separate translation units of a program communicate ([basic.link]) by (for example) calls to functions whose identifiers have external or module linkage, manipulation of objects whose identifiers have external or module linkage, or manipulation of data files.

Translation units can be separately translated and then later linked to produce an executable program.

— _end note_]