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dft_tools/triqs/utility/std_vector_expr_template.hpp
Olivier Parcollet f2c7d449cc First commit : triqs libs version 1.0 alpha1
for earlier commits, see TRIQS0.x repository.
2013-07-17 19:24:07 +02:00

119 lines
5.8 KiB
C++

/*******************************************************************************
*
* TRIQS: a Toolbox for Research in Interacting Quantum Systems
*
* Copyright (C) 2012 by M. Ferrero, O. Parcollet
*
* TRIQS is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* TRIQS. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#ifndef TRIQS_STD_VECTOR_EXPR_TEMPL_H
#define TRIQS_STD_VECTOR_EXPR_TEMPL_H
#include <triqs/utility/expression_template_tools.hpp>
#include <triqs/utility/concept_tools.hpp>
#include <triqs/utility/exceptions.hpp>
#include <vector>
namespace triqs { namespace utility {
// a trait to identify the std::vector ...
TRIQS_DEFINE_CONCEPT_AND_ASSOCIATED_TRAIT(ImmutableStdVector);
template<typename T> struct ImmutableStdVector<std::vector<T>> : std::true_type{};
namespace expr_temp_vec_tools {
template<typename S> struct scalar_wrap {
typedef S value_type;
S s; scalar_wrap(S const &s_):s(s_){}
S operator[](size_t i) const { return s;}
friend std::ostream &operator <<(std::ostream &sout, scalar_wrap const &expr){return sout << expr.s; }
};
// Combine the two sizes of LHS and RHS : need to specialize where there is a scalar
struct combine_size {
template<typename L, typename R>
size_t operator() (L const & l, R const & r) const {
if (!(l.size() == r.size())) TRIQS_RUNTIME_ERROR << "size mismatch : ";//<< l.size()<<" vs" <<r.size();
return l.size();
}
template<typename S, typename R> size_t operator() (scalar_wrap<S> const & w, R const & r) const {return r.size();}
template<typename S, typename L> size_t operator() (L const & l, scalar_wrap<S> const & w) const {return l.size();}
};
template<typename T> struct keeper_type : std::conditional<utility::is_in_ZRC<T>::value, scalar_wrap<T>, T const &> {};
template<typename V>
std::vector<typename V::value_type> make_vector(V const & v) {
std::vector<typename V::value_type> res; res.reserve(v.size());
for (size_t i =0; i<v.size(); ++i) res.push_back( v[i]);
return res;
}
}// std_vec_expr_tools
}}
namespace std { // no choice since the operators are found by ADL..
template<typename Tag, typename L, typename R> struct std_vec_expr : triqs::utility::ImmutableStdVector__concept_tag {
typedef typename triqs::utility::expr_temp_vec_tools::keeper_type<L>::type L_t;
typedef typename triqs::utility::expr_temp_vec_tools::keeper_type<R>::type R_t;
typedef typename std::result_of<triqs::utility::operation<Tag>(typename std::remove_reference<L_t>::type::value_type,
typename std::remove_reference<R_t>::type::value_type)>::type value_t;
typedef value_t value_type;
L_t l; R_t r;
template<typename LL, typename RR> std_vec_expr(LL && l_, RR && r_) : l(std::forward<LL>(l_)), r(std::forward<RR>(r_)) {}
size_t size() const { return triqs::utility::expr_temp_vec_tools::combine_size()(l,r); }
value_type operator[](size_t i) const { return triqs::utility::operation<Tag>()(l[i] , r[i]);}
friend std::ostream &operator <<(std::ostream &sout, std_vec_expr const &expr){return sout << "("<<expr.l << " "<<triqs::utility::operation<Tag>::name << " "<<expr.r<<")" ; }
friend std::vector<value_type> make_vector(std_vec_expr const & v) { return triqs::utility::expr_temp_vec_tools::make_vector(v);}
};
// -------------------------------------------------------------------
//a special case : the unary operator !
template<typename L> struct std_vec_expr_unary : triqs::utility::ImmutableStdVector__concept_tag {
typedef typename triqs::utility::expr_temp_vec_tools::keeper_type<L>::type L_t;
typedef typename L_t::value_type value_type;
L_t l;
template<typename LL> std_vec_expr_unary(LL && l_) : l(std::forward<LL>(l_)) {}
size_t size() const { return l.size(); }
value_type operator[](size_t i) const { return -l[i];}
friend std::ostream &operator <<(std::ostream &sout, std_vec_expr_unary const &expr){return sout << '-'<<expr.l; }
friend std::vector<value_type> make_vector(std_vec_expr_unary const & v) { return triqs::utility::expr_temp_vec_tools::make_vector(v);}
};
// -------------------------------------------------------------------
// Now we can define all the C++ operators ...
#define DEFINE_OPERATOR(TAG, OP, TRAIT1, TRAIT2) \
template<typename A1, typename A2>\
typename std::enable_if<triqs::utility::TRAIT1<A1>::value && triqs::utility::TRAIT2 <A2>::value, std_vec_expr<triqs::utility::tags::TAG, A1,A2>>::type\
operator OP (A1 const & a1, A2 const & a2) { return std_vec_expr<triqs::utility::tags::TAG, A1,A2>(a1,a2);}
DEFINE_OPERATOR(plus, +, ImmutableStdVector,ImmutableStdVector);
DEFINE_OPERATOR(minus, -, ImmutableStdVector,ImmutableStdVector);
DEFINE_OPERATOR(multiplies, *, ImmutableStdVector,ImmutableStdVector);
DEFINE_OPERATOR(multiplies, *, is_in_ZRC,ImmutableStdVector);
DEFINE_OPERATOR(multiplies, *, ImmutableStdVector,is_in_ZRC);
DEFINE_OPERATOR(divides, /, ImmutableStdVector,ImmutableStdVector);
DEFINE_OPERATOR(divides, /, is_in_ZRC,ImmutableStdVector);
DEFINE_OPERATOR(divides, /, ImmutableStdVector,is_in_ZRC);
#undef DEFINE_OPERATOR
// the unary is special
template<typename A1> typename std::enable_if<triqs::utility::ImmutableStdVector<A1>::value, std_vec_expr_unary<A1>>::type
operator - (A1 const & a1) { return std_vec_expr_unary<A1>(a1);}
}
#endif