transform

transform_view

transform_view presents a transformed view of its underlying sequence given a unary Polymorphic Function Object. The transform_view inherits the traversal characteristics (see Sequence Traversal Concept) of its underlying sequence.

Header

#include <boost/fusion/sequence/view/transform_view.hpp>

Synopsis

Unary Version

template <typename Sequence, typename F>
struct transform_view;

Binary Version

template <typename Sequence1, typename Sequence2, typename F>
struct transform_view;

Template parameters

Parameter	Description	Default
`Sequence`	A Forward Sequence
`Sequence1`	A Forward Sequence
`Sequence2`	A Forward Sequence
`F`	A Polymorphic Function Object

Model of

Forward Sequence, Bidirectional Sequence or Random Access Sequence depending on the traversal characteristics (see Sequence Traversal Concept) of its underlying sequence.

Notation

TV: A transform_view type
BTV: A binary transform_view type
UTV: A unary transform_view type
f: An instance of F
s: An instance of Sequence
s1: An instance of Sequence1
s2: An instance of Sequence2
tv, tv2: Instances of transform_view

Expression Semantics

Semantics of an expression is defined only where it differs from, or is not defined in Forward Sequence, Bidirectional Sequence or Random Access Sequence depending on the traversal characteristics (see Sequence Traversal Concept) of its underlying sequence.

Expression	Semantics
`UTV(s, f)`	Creates a unary `transform_view` given sequence, `s` and unary Polymorphic Function Object, `f`.
`BTV(s1, s2, f)`	Creates a binary `transform_view` given sequences, `s1` and `s2` and unary Polymorphic Function Object, `f`.
`TV(tv)`	Copy constructs a `transform_view` from another `transform_view`, `tv`.
`tv = tv2`	Assigns to a `transform_view`, `tv`, from another `transform_view`, `tv2`.

Example

struct square
{
    template <typename T>
    struct result
    {
        typedef T type;
    };

    template <typename T>
    T operator()(T x) const
    {
        return x * x;
    }
};

typedef vector<int, short, double> vector_type;
vector_type vec(2, 5, 3.3);

transform_view<vector_type, square> transform(vec, square());
std::cout << transform << std::endl;