[spanstream.cons] # 31 Input/output library [[input.output]](./#input.output) ## 31.9 Span-based streams [[span.streams]](span.streams#spanstream.cons) ### 31.9.6 Class template basic_spanstream [[spanstream]](spanstream#cons) #### 31.9.6.2 Constructors [spanstream.cons] [🔗](#lib:basic_spanstream,constructor) `explicit basic_spanstream(std::span s, ios_base::openmode which = ios_base::out | ios_bas::in); ` [1](#1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10774) *Effects*: Initializes the base class withbasic_iostream(addressof(*sb*)) and *sb* withbasic_spanbuf(s, which) ([[spanbuf.cons]](spanbuf.cons "31.9.3.2 Constructors"))[.](#1.sentence-1) [🔗](#lib:basic_spanstream,constructor_) `basic_spanstream(basic_spanstream&& rhs); ` [2](#2) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10788) *Effects*: Initializes the base class with std​::​move(rhs) and *sb* with std​::​move(rhs.*sb*)[.](#2.sentence-1) Next, basic_iostream​::​set_rdbuf(addressof(*sb*)) is called to install the contained basic_spanbuf[.](#2.sentence-2)