.TH "std::error_category" 3 "libstdc++" \" -*- nroff -*-
.ad l
.nh
.SH NAME
std::error_category
.SH SYNOPSIS
.br
.PP
.PP
\fR#include <system_error>\fP
.SS "Public Member Functions"

.in +1c
.ti -1c
.RI "\fBerror_category\fP (const error_category &)=delete"
.br
.ti -1c
.RI "virtual \fBerror_condition\fP \fBdefault_error_condition\fP (int __i) const noexcept"
.br
.RI "Return an error_condition corresponding to \fRi\fP in this category\&. "
.ti -1c
.RI "virtual bool \fBequivalent\fP (const \fBerror_code\fP &__code, int __i) const noexcept"
.br
.RI "Test whether \fRcode\fP corresponds to \fRi\fP for this category\&. "
.ti -1c
.RI "virtual bool \fBequivalent\fP (int __i, const \fBerror_condition\fP &__cond) const noexcept"
.br
.RI "Test whether \fRcond\fP corresponds to \fRi\fP for this category\&. "
.ti -1c
.RI "virtual \fBstring\fP \fBmessage\fP (int) const =0"
.br
.RI "A description of the error condition corresponding to the number\&. "
.ti -1c
.RI "virtual const char * \fBname\fP () const noexcept=0"
.br
.RI "A string that identifies the error category\&. "
.ti -1c
.RI "strong_ordering \fBoperator<=>\fP (const error_category &__rhs) const noexcept"
.br
.RI "Ordered comparison that defines a total order for error categories\&. "
.ti -1c
.RI "error_category & \fBoperator=\fP (const error_category &)=delete"
.br
.ti -1c
.RI "bool \fBoperator==\fP (const error_category &__other) const noexcept"
.br
.RI "An error_category only compares equal to itself\&. "
.in -1c
.SH "Detailed Description"
.PP 
Abstract base class for types defining a category of error codes\&.

.PP
An error category defines a context that gives meaning to the integer stored in an \fRerror_code\fP or \fRerror_condition\fP object\&. For example, the standard \fRerrno\fP constants such a \fREINVAL\fP and \fRENOMEM\fP are associated with the "generic" category and other OS-specific error numbers are associated with the "system" category, but a user-defined category might give different meanings to the same numerical values\&.

.PP
A user-defined category can override the \fRequivalent\fP member functions to define correspondence between errors in different categories\&. For example, a category for errors from disk I/O could consider some of its error numbers equivalent to ENOSPC and ENOENT in the generic category\&.

.PP
\fBSince\fP
.RS 4
C++11 
.RE
.PP

.SH "Member Function Documentation"
.PP 
.SS "virtual \fBerror_condition\fP std::error_category::default_error_condition (int __i) const\fR [virtual]\fP, \fR [noexcept]\fP"

.PP
Return an error_condition corresponding to \fRi\fP in this category\&. 
.SS "virtual bool std::error_category::equivalent (const \fBerror_code\fP & __code, int __i) const\fR [virtual]\fP, \fR [noexcept]\fP"

.PP
Test whether \fRcode\fP corresponds to \fRi\fP for this category\&. 
.SS "virtual bool std::error_category::equivalent (int __i, const \fBerror_condition\fP & __cond) const\fR [virtual]\fP, \fR [noexcept]\fP"

.PP
Test whether \fRcond\fP corresponds to \fRi\fP for this category\&. 
.SS "virtual \fBstring\fP std::error_category::message (int ) const\fR [pure virtual]\fP"

.PP
A description of the error condition corresponding to the number\&. 
.PP
References \fBmessage()\fP\&.
.PP
Referenced by \fBmessage()\fP, \fBstd::error_code::message()\fP, and \fBstd::error_condition::message()\fP\&.
.SS "virtual const char * std::error_category::name () const\fR [pure virtual]\fP, \fR [noexcept]\fP"

.PP
A string that identifies the error category\&. 
.SS "strong_ordering std::error_category::operator<=> (const error_category & __rhs) const\fR [inline]\fP, \fR [nodiscard]\fP, \fR [noexcept]\fP"

.PP
Ordered comparison that defines a total order for error categories\&. 
.PP
References \fBoperator<=>()\fP\&.
.PP
Referenced by \fBoperator<=>()\fP\&.
.SS "bool std::error_category::operator== (const error_category & __other) const\fR [inline]\fP, \fR [noexcept]\fP"

.PP
An error_category only compares equal to itself\&. 

.SH "Author"
.PP 
Generated automatically by Doxygen for libstdc++ from the source code\&.