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find_first_of.hpp
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1 // Range v3 library
3 //
4 // Copyright Eric Niebler 2014-present
5 //
6 // Use, modification and distribution is subject to the
7 // Boost Software License, Version 1.0. (See accompanying
8 // file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
10 //
11 // Project home: https://github.com/ericniebler/range-v3
12 //
13 #ifndef RANGES_V3_ALGORITHM_FIND_FIRST_OF_HPP
14 #define RANGES_V3_ALGORITHM_FIND_FIRST_OF_HPP
15 
16 #include <utility>
17 
18 #include <range/v3/range_fwd.hpp>
19 
29 #include <range/v3/utility/static_const.hpp>
30 
31 #include <range/v3/detail/prologue.hpp>
32 
33 namespace ranges
34 {
37  RANGES_FUNC_BEGIN(find_first_of)
38  // Rationale: return I0 instead of pair<I0,I1> because find_first_of need
39  // not actually compute the end of [I1,S0); therefore, it is not necessarily
40  // losing information. E.g., if begin0 == end0, we can return begin0 immediately.
41  // If we returned pair<I0,I1>, we would need to do an O(N) scan to find the
42  // end position.
43 
44 
45  template(typename I0,
46  typename S0,
47  typename I1,
48  typename S1,
49  typename R = equal_to,
50  typename P0 = identity,
51  typename P1 = identity)(
52  requires input_iterator<I0> AND sentinel_for<S0, I0> AND
53  forward_iterator<I1> AND sentinel_for<S1, I1> AND
54  indirect_relation<R, projected<I0, P0>, projected<I1, P1>>)
55  constexpr I0 RANGES_FUNC(find_first_of)(I0 begin0,
56  S0 end0,
57  I1 begin1,
58  S1 end1,
59  R pred = R{},
60  P0 proj0 = P0{},
61  P1 proj1 = P1{}) //
62  {
63  for(; begin0 != end0; ++begin0)
64  for(auto tmp = begin1; tmp != end1; ++tmp)
65  if(invoke(pred, invoke(proj0, *begin0), invoke(proj1, *tmp)))
66  return begin0;
67  return begin0;
68  }
69 
71  template(typename Rng0,
72  typename Rng1,
73  typename R = equal_to,
74  typename P0 = identity,
75  typename P1 = identity)(
76  requires input_range<Rng0> AND forward_range<Rng1> AND
78  projected<iterator_t<Rng0>, P0>,
79  projected<iterator_t<Rng1>, P1>>)
80  constexpr borrowed_iterator_t<Rng0> RANGES_FUNC(find_first_of)(
81  Rng0 && rng0, Rng1 && rng1, R pred = R{}, P0 proj0 = P0{}, P1 proj1 = P1{}) //
82  {
83  return (*this)(begin(rng0),
84  end(rng0),
85  begin(rng1),
86  end(rng1),
87  std::move(pred),
88  std::move(proj0),
89  std::move(proj1));
90  }
91 
92  RANGES_FUNC_END(find_first_of)
93 
94  namespace cpp20
95  {
96  using ranges::find_first_of;
97  }
99 } // namespace ranges
100 
101 #include <range/v3/detail/epilogue.hpp>
102 
103 #endif
template(typename Rng0, typename Rng1, typename R=equal_to, typename P0=identity, typename P1=identity)(requires input_range< Rng0 > AND forward_range< Rng1 > AND indirect_relation< R
This is an overloaded member function, provided for convenience. It differs from the above function o...
CPP_concept sentinel_for
\concept sentinel_for
Definition: concepts.hpp:306
CPP_concept input_iterator
\concept input_iterator
Definition: concepts.hpp:362
CPP_concept indirect_relation
\concept indirect_relation
Definition: concepts.hpp:670
CPP_concept forward_iterator
\concept forward_iterator
Definition: concepts.hpp:370
decltype(begin(declval(Rng &))) iterator_t
Definition: access.hpp:698
typename Fn::template invoke< Args... > invoke
Evaluate the invocable Fn with the arguments Args.
Definition: meta.hpp:541
bool_< T::type::value==U::type::value > equal_to
A Boolean integral constant wrapper around the result of comparing T::type::value and U::type::value ...
Definition: meta.hpp:237
Definition: comparisons.hpp:28
Definition: identity.hpp:25