Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for an old version of Boost. Click here to view this page for the latest version.
PrevUpHomeNext
make_map
Description

Returns the result type of make_map.

The implementation depends on the support of variadic templates.

When variadic templates are not supported, make_map is a metafunction of the form:

Synopsis
template <
    typename K0, typename K1,... typename KN
  , typename T0, typename T1,... typename TN>
struct make_map;

For C++11 compilers, the variadic function interface has no upper bound.

For C++03 compilers, the variadic function accepts 0 to FUSION_MAX_MAP_SIZE elements, where FUSION_MAX_MAP_SIZE is a user definable predefined maximum that defaults to 10. You may define the preprocessor constant FUSION_MAX_MAP_SIZE before including any Fusion header to change the default. Example:

#define FUSION_MAX_MAP_SIZE 20

When variadic templates are supported, make_map is a metafunction class of the form:

Synopsis
template <
    typename K0, typename K1,... typename KN>
struct make_map
{
    struct apply<
    typename T0, typename T1,... typename TN>
};
Parameters

Parameter

Requirement

Description

K0, K1,... KN

Any type

Keys associated with T0, T1,... TN

T0, T1,... TN

Any type

Data associated with keys K0, K1,... KN

Expression Semantics
#if !defined(BOOST_FUSION_HAS_VARIADIC_MAP)
resulf_of::make_map<K0, K1,... KN, T0, T1,... TN>::type;
#else
resulf_of::make_map<K0, K1,... KN>::apply<T0, T1,... TN>::type;
#endif

Return type: result_of::make_map<K0, K0,... KN, T0, T1,... TN>::type when variadic templates are not supported, or result_of::make_map<K0, K0,... KN>::apply<T0, T1,... TN>::type when variadic templates are supported.

Semantics: A map with fusion::pair elements where the second_type is converted following the rules for element conversion.

Precondition: There may be no duplicate key types.

Header
#include <boost/fusion/container/generation/make_map.hpp>
#include <boost/fusion/include/make_map.hpp>
Example
#if !defined(BOOST_FUSION_HAS_VARIADIC_MAP)
result_of::make_map<int, double, char, double>::type
#else
result_of::make_map<int, double>::apply<char, double>::type
#endif
See also

fusion::pair


PrevUpHomeNext