none

Description

For a sequence seq and unary function object f, none returns true if f returns false for every element of seq.

Synopsis

template<
    typename Sequence,
    typename F
    >
typename result_of::none<Sequence,F>::type none(
    Sequence const& seq, F f);

Table 1.40. Parameters

Parameter	Requirement	Description
`seq`	A model of Forward Sequence, `f(e)` is a valid expression, convertible to `bool`, for every element `e` in `seq`	The sequence to search
`f`	A unary function object	The search predicate

Expression Semantics

none(seq, f);

Return type: bool

Semantics: Returns true if and only if f(e) evaluates to false for every element e in seq. Result equivalent to !any(seq, f).

Complexity

Linear. At most result_of::size<Sequence>::value comparisons.

Header

#include <boost/fusion/algorithm/query/none.hpp>

Example

struct odd
{
    template<typename T>
    bool operator()(T t) const
    {
        return t % 2;
    }
};
...
assert(none(make_vector(2,4), odd()));
assert(!none(make_vector(1,2), odd()));