Linux Manuals

std::Invocable,std::RegularInvocable – std::Invocable,std::RegularInvocable Synopsis Defined in header <concepts> template< class F, class… Args > concept Invocable = requires(F&& f, Args&&… args) { (since C++20) std::invoke(std::forward<F>(f), std::forward<Args>(args)…); /* not required to be equality preserving */ }; template< class F, class… Args > (since C++20) concept RegularInvocable = std::Invocable<F, Args…>; The Invocable concept specifies that a callable…

std::Integral – std::Integral Synopsis Defined in header <concepts> template < class T > (since C++20) concept Integral = std::is_integral_v<T>; The concept Integral<T> is satisfied if and only if T is an integral type. See also is_integral checks if a type is an integral type             (class template) (C++11)

std::EqualityComparable,std::EqualityComparableWith – std::EqualityComparable,std::EqualityComparableWith Synopsis Defined in header<concepts> template <class T, class U> concept __WeaklyEqualityComparableWith = // exposition only requires(const std::remove_reference_t<T> &t, const std::remove_reference_t<U> &u) { t == u; requires std::Boolean<decltype(t == u)>; (1) t != u; requires std::Boolean<decltype(t != u)>; u == t; requires std::Boolean<decltype(u == t)>; u != t; requires std::Boolean<decltype(u != t)>; };…

std::Destructible – std::Destructible Synopsis Defined in header <concepts> template < class T > (since C++20) concept Destructible = std::is_nothrow_destructible_v<T>; The concept Destructible specifies the concept of all types whose instances can safely be destroyed at the end of their lifetime (including reference types). Notes Unlike the Destructible named requirement, std::Destructible requires the destructor to be…

std::DerivedFrom – std::DerivedFrom Synopsis Defined in header<concepts> template <class Derived, class Base> concept DerivedFrom = (since C++ 20) std::is_base_of_v<Base, Derived> && std::is_convertible_v<const volatile Derived *, const volatile Base *>; The concept DerivedFrom<Derived, Base> is satisfied if and only if Base is a class type that is either Derived or a public and unambiguous base of…

std::DefaultConstructible – std::DefaultConstructible Synopsis Defined in header <concepts> template < class T > (since C++20) concept DefaultConstructible = std::Constructible<T>; The DefaultConstructible concept provides a shorthand for the common case when the question is whether a type can be constructed with no arguments. See also Constructible specifies that a variable of the type can be constructed…

std::Copyable – std::Copyable Synopsis Defined in header<concepts> template <class T> concept Copyable = std::CopyConstructible<T> &&(since C++ 20) std::Movable<T> && std::Assignable<T &, const T &>; The concept Copyable<T> specifies that T is an Movable object type that can also copied (that is, it supports copy construction and copy assignment). Notes It is intended that Copyable<T> also…

std::CopyConstructible – std::CopyConstructible Synopsis Defined in header<concepts> template <class T> concept CopyConstructible = std::MoveConstructible<T> &&(since C++ 20) std::Constructible<T, T &> && std::ConvertibleTo<T &, T> && std::Constructible<T, const T &> && std::ConvertibleTo<const T &, T> && std::Constructible<T, const T> && std::ConvertibleTo<const T, T>; The concept CopyConstructible is satisfied if T is an lvalue reference type, or…

std::ConvertibleTo – std::ConvertibleTo Synopsis Defined in header <concepts> template <class From, class To> concept ConvertibleTo = std::is_convertible_v<From, To> && (since C++20) requires(From (&f)()) { static_cast<To>(f()); }; The concept ConvertibleTo<From, To> specifies that an expression of the type and value category specified by From can be implicitly and explicitly converted to the type To, and the…

std::Constructible – std::Constructible Synopsis Defined in header <concepts> template < class T, class… Args > concept Constructible = (since C++20) std::Destructible<T> && std::is_constructible_v<T, Args…>; The Constructible concept specifies that a variable of type T can be initialized with the given set of argument types Args…. See also is_constructible is_trivially_constructible is_nothrow_constructible checks if a type has…

std::CommonReference – std::CommonReference Synopsis Defined in header <concepts> template < class T, class U > concept CommonReference = std::Same<std::common_reference_t<T, U>, std::common_reference_t<U, T>> && (since C++20) std::ConvertibleTo<T, std::common_reference_t<T, U>> && std::ConvertibleTo<U, std::common_reference_t<T, U>>; The concept CommonReference<T, U> specifies that two types T and U share a common reference type (as computed by std::common_reference_t) to which both…

std::Common – std::Common Synopsis Defined in header<concepts> template <class T, class U> concept Common = std::Same<std::common_type_t<T, U>, std::common_type_t<U, T>> && requires { static_cast<std::common_type_t<T, U>>(std::declval<T>()); static_cast<std::common_type_t<T, U>>(std::declval<U>()); } && std::CommonReference<(since C++ 20) std::add_lvalue_reference_t<const T>, std::add_lvalue_reference_t<const U>> && std::CommonReference< std::add_lvalue_reference_t<std::common_type_t<T, U>>, std::common_reference_t< std::add_lvalue_reference_t<const T>, std::add_lvalue_reference_t<const U>>>; The concept Common<T, U> specifies that two types T and U…

std::Boolean – std::Boolean Synopsis Defined in header<concepts> template <class B> concept Boolean = std::Movable<std::remove_cvref_t<B>> && requires(const std::remove_reference_t<B> &b1, const std::remove_reference_t<B> &b2, const bool a) { requires std::ConvertibleTo < const std::remove_reference_t<B> &, bool > ; !b1; requires std::ConvertibleTo<decltype(!b1), bool>; b1 &&a; requires std::Same<decltype(b1 && a), bool>; b1 || a; requires std::Same<decltype(b1 || a), bool>; b1 &&b2;…

std::Assignable – std::Assignable Synopsis Defined in header<concepts> template <class LHS, class RHS> concept Assignable = std::is_lvalue_reference_v<LHS> && std::CommonReference < const std::remove_reference_t<LHS> &, (since C++ 20) const std::remove_reference_t<RHS> & > && requires(LHS lhs, RHS &&rhs) { lhs = std::forward<RHS>(rhs); requires std::Same<decltype(lhs = std::forward<RHS>(rhs)), LHS>; }; The concept Assignable<LHS, RHS> specifies that an expression of the type…

stbtrs.f – Synopsis Functions/Subroutines subroutine stbtrs (UPLO, TRANS, DIAG, N, KD, NRHS, AB, LDAB, B, LDB, INFO) STBTRS Function/Subroutine Documentation subroutine stbtrs (characterUPLO, characterTRANS, characterDIAG, integerN, integerKD, integerNRHS, real, dimension( ldab, * )AB, integerLDAB, real, dimension( ldb, * )B, integerLDB, integerINFO) STBTRS Purpose: STBTRS solves a triangular system of the form A * X =…

stbsv.f – Synopsis Functions/Subroutines subroutine stbsv (UPLO, TRANS, DIAG, N, K, A, LDA, X, INCX) STBSV Function/Subroutine Documentation subroutine stbsv (characterUPLO, characterTRANS, characterDIAG, integerN, integerK, real, dimension(lda,*)A, integerLDA, real, dimension(*)X, integerINCX) STBSV Purpose: STBSV solves one of the systems of equations A*x = b, or A**T*x = b, where b and x are n element…

stbrfs.f – Synopsis Functions/Subroutines subroutine stbrfs (UPLO, TRANS, DIAG, N, KD, NRHS, AB, LDAB, B, LDB, X, LDX, FERR, BERR, WORK, IWORK, INFO) STBRFS Function/Subroutine Documentation subroutine stbrfs (characterUPLO, characterTRANS, characterDIAG, integerN, integerKD, integerNRHS, real, dimension( ldab, * )AB, integerLDAB, real, dimension( ldb, * )B, integerLDB, real, dimension( ldx, * )X, integerLDX, real, dimension( *…

stbmv.f – Synopsis Functions/Subroutines subroutine stbmv (UPLO, TRANS, DIAG, N, K, A, LDA, X, INCX) STBMV Function/Subroutine Documentation subroutine stbmv (characterUPLO, characterTRANS, characterDIAG, integerN, integerK, real, dimension(lda,*)A, integerLDA, real, dimension(*)X, integerINCX) STBMV Purpose: STBMV performs one of the matrix-vector operations x := A*x, or x := A**T*x, where x is an n element vector and…

stbcon.f – Synopsis Functions/Subroutines subroutine stbcon (NORM, UPLO, DIAG, N, KD, AB, LDAB, RCOND, WORK, IWORK, INFO) STBCON Function/Subroutine Documentation subroutine stbcon (characterNORM, characterUPLO, characterDIAG, integerN, integerKD, real, dimension( ldab, * )AB, integerLDAB, realRCOND, real, dimension( * )WORK, integer, dimension( * )IWORK, integerINFO) STBCON Purpose: STBCON estimates the reciprocal of the condition number of a…

statvfs, fstatvfs – get filesystem statistics Synopsis #include <sys/statvfs.h> int statvfs(const char *path, struct statvfs *buf); int fstatvfs(int fd, struct statvfs *buf); Description The function statvfs() returns information about a mounted filesystem. path is the pathname of any file within the mounted filesystem. buf is a pointer to a statvfs structure defined approximately as follows:…