.TH "cereal::NameValuePair< T >" 3 "Sat Aug 29 2026 00:42:30" "cereal" \" -*- nroff -*-
.ad l
.nh
.SH NAME
cereal::NameValuePair< T > \- For holding name value pairs\&.  

.SH SYNOPSIS
.br
.PP
.PP
\fR#include </home/build/include/cereal/details/helpers\&.hpp>\fP
.PP
Inherits \fBcereal::detail::NameValuePairCore\fP\&.
.SS "Public Member Functions"

.in +1c
.ti -1c
.RI "\fBNameValuePair\fP (char const *n, T &&v)"
.br
.RI "Constructs a new \fBNameValuePair\fP\&. "
.in -1c
.SS "Public Attributes"

.in +1c
.ti -1c
.RI "char const  * \fBname\fP"
.br
.ti -1c
.RI "Type \fBvalue\fP"
.br
.in -1c
.SS "Related Symbols"
(Note that these are not member symbols\&.) 
.in +1c
.ti -1c
.RI "template<class T> \fBNameValuePair\fP< T > \fBmake_nvp\fP (std::string const &name, T &&value)"
.br
.RI "Creates a name value pair\&. "
.ti -1c
.RI "template<class T> \fBNameValuePair\fP< T > \fBmake_nvp\fP (const char *name, T &&value)"
.br
.RI "Creates a name value pair\&. "
.ti -1c
.RI "template<class Archive, class T> std::enable_if< std::is_same< Archive,\fB::cereal::BinaryInputArchive\fP >::value||std::is_same< Archive,\fB::cereal::BinaryOutputArchive\fP >::value, T && >::type \fBmake_nvp\fP (const char *, T &&value)"
.br
.RI "A specialization of make_nvp<> that simply forwards the value for binary archives\&. "
.ti -1c
.RI "template<class Archive, class T> std::enable_if<!std::is_same< Archive,\fB::cereal::BinaryInputArchive\fP >::value &&!std::is_same< Archive,\fB::cereal::BinaryOutputArchive\fP >::value, \fBNameValuePair\fP< T > >::type \fBmake_nvp\fP (const char *name, T &&value)"
.br
.RI "A specialization of make_nvp<> that actually creates an nvp for non-binary archives\&. "
.in -1c
.SH "Detailed Description"
.PP 

.SS "template<class T>
.br
class cereal::NameValuePair< T >"For holding name value pairs\&. 

This pairs a name (some string) with some value such that an archive can potentially take advantage of the pairing\&.

.PP
In serialization functions, NameValuePairs are usually created like so: 
.PP
.nf
struct MyStruct
{
  int a, b, c, d, e;

  template<class Archive>
  void serialize(Archive & archive)
  {
    archive( CEREAL_NVP(a),
             CEREAL_NVP(b),
             CEREAL_NVP(c),
             CEREAL_NVP(d),
             CEREAL_NVP(e) );
  }
};

.fi
.PP

.PP
Alternatively, you can give you data members custom names like so: 
.PP
.nf
struct MyStruct
{
  int a, b, my_embarrassing_variable_name, d, e;

  template<class Archive>
  void serialize(Archive & archive)
  {
    archive( CEREAL_NVP(a),
             CEREAL_NVP(b),
             cereal::make_nvp("var", my_embarrassing_variable_name) );
             CEREAL_NVP(d),
             CEREAL_NVP(e) );
  }
};

.fi
.PP

.PP
There is a slight amount of overhead to creating NameValuePairs, so there is a third method which will elide the names when they are not used by the Archive:

.PP
.PP
.nf
struct MyStruct
{
  int a, b;

  template<class Archive>
  void serialize(Archive & archive)
  {
    archive( cereal::make_nvp<Archive>(a),
             cereal::make_nvp<Archive>(b) );
  }
};
.fi
.PP

.PP
This third method is generally only used when providing generic type support\&. Users writing their own serialize functions will normally explicitly control whether they want to use NVPs or not\&. 
.SH "Constructor & Destructor Documentation"
.PP 
.SS "template<class T> \fBcereal::NameValuePair\fP< T >::NameValuePair (char const * n, T && v)\fR [inline]\fP"

.PP
Constructs a new \fBNameValuePair\fP\&. 
.PP
\fBParameters\fP
.RS 4
\fIn\fP The name of the pair 
.br
\fIv\fP The value to pair\&. Ideally this should be an l-value reference so that the value can be both loaded and saved to\&. If you pass an r-value reference, the \fBNameValuePair\fP will store a copy of it instead of a reference\&. Thus you should only pass r-values in cases where this makes sense, such as the result of some size() call\&. 
.RE
.PP


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