[numeric.requirements] # 29 Numerics library [[numerics]](./#numerics) ## 29.2 Numeric type requirements [numeric.requirements] [1](#1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L35) Thecomplex andvalarray components are parameterized by the type of information they contain and manipulate[.](#1.sentence-1) A C++ program shall instantiate these components only with a numeric type[.](#1.sentence-2) A [*numeric type*](#def:type,numeric "29.2 Numeric type requirements [numeric.requirements]") is a cv-unqualified object type T that meets the[*Cpp17DefaultConstructible*](utility.arg.requirements#:Cpp17DefaultConstructible "16.4.4.2 Template argument requirements [utility.arg.requirements]"),[*Cpp17CopyConstructible*](utility.arg.requirements#:Cpp17CopyConstructible "16.4.4.2 Template argument requirements [utility.arg.requirements]"),[*Cpp17CopyAssignable*](utility.arg.requirements#:Cpp17CopyAssignable "16.4.4.2 Template argument requirements [utility.arg.requirements]"), and[*Cpp17Destructible*](utility.arg.requirements#:Cpp17Destructible "16.4.4.2 Template argument requirements [utility.arg.requirements]") requirements ([[utility.arg.requirements]](utility.arg.requirements "16.4.4.2 Template argument requirements"))[.](#1.sentence-3)[239](#footnote-239 "In other words, value types. These include arithmetic types, pointers, the library class complex, and instantiations of valarray for value types.") [2](#2) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L59) If any operation on T throws an exception the effects are undefined[.](#2.sentence-1) [3](#3) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L63) In addition, many member and related functions ofvalarray can be successfully instantiated and will exhibit well-defined behavior if and only ifT meets additional requirements specified for each such member or related function[.](#3.sentence-1) [4](#4) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L71) [*Example [1](#example-1)*: It is valid to instantiatevalarray, butoperator>() will not be successfully instantiated forvalarray operands, sincecomplex does not have any ordering operators[.](#4.sentence-1) — *end example*] [239)](#footnote-239)[239)](#footnoteref-239) In other words, value types[.](#footnote-239.sentence-1) These include arithmetic types, pointers, the library classcomplex, and instantiations ofvalarray for value types[.](#footnote-239.sentence-2)