[syserr.errcondition.observers]

# 19 Diagnostics library [[diagnostics]](./#diagnostics)

## 19.5 System error support [[syserr]](syserr#errcondition.observers)

### 19.5.5 Class error_condition [[syserr.errcondition]](syserr.errcondition#observers)

#### 19.5.5.4 Observers [syserr.errcondition.observers]

[ð](#lib:value,error_condition)

`int value() const noexcept;
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L1379)

*Returns*: *val_*[.](#1.sentence-1)

[ð](#lib:category,error_condition)

`const error_category& category() const noexcept;
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L1390)

*Returns*: **cat_*[.](#2.sentence-1)

[ð](#lib:message,error_condition)

`string message() const;
`

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L1401)

*Returns*: category().message(value())[.](#3.sentence-1)

[ð](#lib:operator_bool,error_condition)

`explicit operator bool() const noexcept;
`

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L1412)

*Returns*: value() != 0[.](#4.sentence-1)
