[invalid.argument]

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

## 19.2 Exception classes [[std.exceptions]](std.exceptions#invalid.argument)

### 19.2.5 Class invalid_argument [invalid.argument]

[ð](#lib:invalid_argument)

namespace std {class invalid_argument : public logic_error {public:constexpr explicit invalid_argument(const string& what_arg); constexpr explicit invalid_argument(const char* what_arg); };}

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L175)

The classinvalid_argument defines the type of objects thrown as exceptions to report an invalid argument[.](#1.sentence-1)

[ð](#lib:invalid_argument,constructor)

`constexpr invalid_argument(const string& what_arg);
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L186)

*Postconditions*: strcmp(what(), what_arg.c_str()) == 0[.](#2.sentence-1)

[ð](#lib:invalid_argument,constructor_)

`constexpr invalid_argument(const char* what_arg);
`

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/diagnostics.tex#L197)

*Postconditions*: strcmp(what(), what_arg) == 0[.](#3.sentence-1)
