[protection.within.classes]

# 16 Library introduction [[library]](./#library)

## 16.4 Library-wide requirements [[requirements]](requirements#protection.within.classes)

### 16.4.6 Conforming implementations [[conforming]](conforming#protection.within.classes)

#### 16.4.6.12 Protection within classes [protection.within.classes]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/lib-intro.tex#L3847)

It is unspecified whether any function signature or class described in[[support]](support "17 Language support library") through [[exec]](exec "33 Execution control library") and [[depr]](depr "Annex D (normative) Compatibility features") is a
friend of another class in the C++ standard library[.](#1.sentence-1)