[lex.separate]

# 5 Lexical conventions [[lex]](./#lex)

## 5.1 Separate translation [lex.separate]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/lex.tex#L27)

The text of the program is kept in units called[*source files*](#def:source_file "5.1 Separate translation [lex.separate]") in this document[.](#1.sentence-1)

A source file together with all the <headers> and source files [included](cpp.include "15.3 Source file inclusion [cpp.include]") via the preprocessing
directive #include, less any source lines skipped by any of the
conditional inclusion ([[cpp.cond]](cpp.cond "15.2 Conditional inclusion")) preprocessing directives,
as modified by the implementation-defined behavior of any
conditionally-supported-directives ([[cpp.pre]](cpp.pre "15.1 Preamble")) and pragmas ([[cpp.pragma]](cpp.pragma "15.10 Pragma directive")),
if any, is
called a [*preprocessing translation unit*](#def:translation_unit,preprocessing "5.1 Separate translation [lex.separate]")[.](#1.sentence-2)

[*Note [1](#note-1)*:

A C++ program need not all be translated at the same time[.](#1.sentence-3)

Translation units can be separately translated and then later linked
to produce an executable program ([[basic.link]](basic.link "6.7 Program and linkage"))[.](#1.sentence-4)

â *end note*]
