[syserr.errcode.constructors]

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

## 19.5 System error support [[syserr]](syserr#errcode.constructors)

### 19.5.4 Class error_code [[syserr.errcode]](syserr.errcode#constructors)

#### 19.5.4.2 Constructors [syserr.errcode.constructors]

[🔗](#lib:error_code,constructor)

`error_code() noexcept;
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L1064)

*Effects*: Initializes *val_* with 0 and *cat_* with &system_category()[.](#1.sentence-1)

[🔗](#lib:error_code,constructor_)

`error_code(int val, const error_category& cat) noexcept;
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L1076)

*Effects*: Initializes *val_* with val and *cat_* with &cat[.](#2.sentence-1)

[🔗](#lib:error_code,constructor__)

`template<class ErrorCodeEnum>
  error_code(ErrorCodeEnum e) noexcept;
`

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L1089)

*Constraints*: [is_error_code_enum_v](system.error.syn#lib:is_error_code_enum_v "19.5.2 Header <system_­error> synopsis [system.error.syn]")<ErrorCodeEnum> is true[.](#3.sentence-1)

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L1093)

*Effects*: Equivalent to:error_code ec = make_error_code(e);
assign(ec.value(), ec.category());