set

Description

set is an Associative Sequence of heteregenous typed data elements. Type identity is used to impose an equivalence relation on keys. The element's type is its key. A set may contain at most one element for each key. Membership testing and element key lookup has constant runtime complexity (see Overloaded Functions).

Header

#include <boost/fusion/sequence/container/set.hpp>

Synopsis

template <
    typename T0 = unspecified
  , typename T1 = unspecified
  , typename T2 = unspecified
    ...
  , typename TN = unspecified
>
struct set;

The variadic class interface accepts 0 to FUSION_MAX_SET_SIZE elements, where FUSION_MAX_SET_SIZE is a user definable predefined maximum that defaults to 10. Example:

set<int, char, double>

You may define the preprocessor constant FUSION_MAX_SET_SIZE before including any Fusion header to change the default. Example:

#define FUSION_MAX_SET_SIZE 20

Template parameters

Parameter	Description	Default
`T0`...`TN`	Element types	unspecified-type

Model of

Notation

S: A set type
s: An instance of set
e0...en: Heterogeneous values
fs: A Forward Sequence

Expression Semantics

Semantics of an expression is defined only where it differs from, or is not defined in Random Access Sequence and Associative Sequence.

Expression	Semantics
`S()`	Creates a set with default constructed elements.
`S(e0, e1,... en)`	Creates a set with elements `e0`...`en`.
`S(fs)`	Copy constructs a set from a Forward Sequence `fs`.
`s = fs`	Assigns to a set, `s`, from a Forward Sequence `fs`.

Example

typedef set<int, float> S;
S s(12, 5.5f);
std::cout << at_key<int>(s) << std::endl;
std::cout << at_key<float>(s) << std::endl;
std::cout << result_of::has_key<S, double>::value << std::endl;