Dune Core Modules (2.9.0)

dotproduct.hh
Go to the documentation of this file.
1 // -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 // vi: set et ts=4 sw=2 sts=2:
3 // SPDX-FileCopyrightInfo: Copyright (C) DUNE Project contributors, see file LICENSE.md in module root
4 // SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception
5 #ifndef DUNE_DOTPRODUCT_HH
6 #define DUNE_DOTPRODUCT_HH
7 
8 #include "ftraits.hh"
9 #include "typetraits.hh"
10 
11 namespace Dune {
26  template<class T, class = void>
27  struct IsVector : std::false_type {};
28 
29  template<class T>
30  struct IsVector<T, std::void_t<typename T::field_type> >
31  : std::true_type {};
32 
40  template<class A, class B>
41  auto
42  dot(const A & a, const B & b) -> typename std::enable_if<IsNumber<A>::value && !IsVector<A>::value && !std::is_same<typename FieldTraits<A>::field_type,typename FieldTraits<A>::real_type> ::value, decltype(conj(a)*b)>::type
43  {
44  return conj(a)*b;
45  }
46 
56  // fundamental type with A being a real type
57  template<class A, class B>
58  auto
59  dot(const A & a, const B & b) -> typename std::enable_if<IsNumber<A>::value && !IsVector<A>::value && std::is_same<typename FieldTraits<A>::field_type,typename FieldTraits<A>::real_type>::value, decltype(a*b)>::type
60  {
61  return a*b;
62  }
63 
73  template<typename A, typename B>
74  auto
75  dot(const A & a, const B & b) -> typename std::enable_if<IsVector<A>::value, decltype(a.dot(b))>::type
76  {
77  return a.dot(b);
78  }
88  template<class A, class B>
89  auto
90  dotT(const A & a, const B & b) -> decltype(a*b)
91  {
92  return a*b;
93  }
94 
96 } // end namespace DUNE
97 
98 #endif // DUNE_DOTPRODUCT_HH
Type traits to determine the type of reals (when working with complex numbers)
auto dot(const A &a, const B &b) -> typename std::enable_if< IsNumber< A >::value &&!IsVector< A >::value &&!std::is_same< typename FieldTraits< A >::field_type, typename FieldTraits< A >::real_type > ::value, decltype(conj(a) *b)>::type
computes the dot product for fundamental data types according to Petsc's VectDot function: dot(a,...
Definition: dotproduct.hh:42
typename Impl::voider< Types... >::type void_t
Is void for all valid input types. The workhorse for C++11 SFINAE-techniques.
Definition: typetraits.hh:40
Dune namespace.
Definition: alignedallocator.hh:13
auto dotT(const A &a, const B &b) -> decltype(a *b)
Computes an indefinite vector dot product for fundamental data types according to Petsc's VectTDot fu...
Definition: dotproduct.hh:90
Creative Commons License   |  Legal Statements / Impressum  |  Hosted by TU Dresden  |  generated with Hugo v0.80.0 (May 4, 22:30, 2024)