Add support for mp_product<F>

This commit is contained in:
Peter Dimov
2020-06-03 15:08:49 +03:00
parent d709610087
commit 10ba80acb9
3 changed files with 25 additions and 9 deletions

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@@ -262,7 +262,8 @@ Same as `mp_repeat_c` but with a type argument `N`. The number of copies is `N::
`mp_product<F, L1<T1...>, L2<T2...>, ..., Ln<Tn...>>` evaluates `F<U1, U2, ..., Un>` for values `Ui` taken from `mp_product<F, L1<T1...>, L2<T2...>, ..., Ln<Tn...>>` evaluates `F<U1, U2, ..., Un>` for values `Ui` taken from
the Cartesian product of the lists, as if the elements `Ui` are formed by `n` nested loops, each traversing `Li`. the Cartesian product of the lists, as if the elements `Ui` are formed by `n` nested loops, each traversing `Li`.
It returns a list of the form `L1<V...>` containing the results of the application of `F`. It returns a list of the form `L1<V...>` containing the results of the application of `F`. The degenerate case
of zero lists, `mp_product<F>`, returns `mp_list<F<>>`.
.mp_product on two lists .mp_product on two lists
[cols="<.^4m,4*^.^1m",width=85%] [cols="<.^4m,4*^.^1m",width=85%]

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@@ -254,7 +254,9 @@ template<class L, class N> using mp_repeat = typename detail::mp_repeat_c_impl<L
namespace detail namespace detail
{ {
template<template<class...> class F, class P, class... L> struct mp_product_impl_2; template<template<class...> class F, class P, class... L> struct mp_product_impl_2
{
};
template<template<class...> class F, class P> struct mp_product_impl_2<F, P> template<template<class...> class F, class P> struct mp_product_impl_2<F, P>
{ {
@@ -266,7 +268,14 @@ template<template<class...> class F, class P, template<class...> class L1, class
using type = mp_append<typename mp_product_impl_2<F, mp_push_back<P, T1>, L...>::type...>; using type = mp_append<typename mp_product_impl_2<F, mp_push_back<P, T1>, L...>::type...>;
}; };
template<template<class...> class F, class... L> struct mp_product_impl; template<template<class...> class F, class... L> struct mp_product_impl
{
};
template<template<class...> class F> struct mp_product_impl<F>
{
using type = mp_list< F<> >;
};
template<template<class...> class F, class L1, class... L> struct mp_product_impl<F, L1, L...> template<template<class...> class F, class L1, class... L> struct mp_product_impl<F, L1, L...>
{ {

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@@ -24,9 +24,10 @@ struct Y1 {};
struct Z1 {}; struct Z1 {};
struct Z2 {}; struct Z2 {};
template<class T1, class T2, class T3> struct F {};
template<class T> struct F1 {}; template<class T> struct F1 {};
template<class T1, class T2, class T3> struct F3 {};
template<class...> struct F {};
int main() int main()
{ {
@@ -40,8 +41,8 @@ int main()
using L2 = mp_list<Y1>; using L2 = mp_list<Y1>;
using L3 = std::pair<Z1, Z2>; using L3 = std::pair<Z1, Z2>;
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product<F, L1, L2, L3>, std::tuple<F<X1, Y1, Z1>, F<X1, Y1, Z2>, F<X2, Y1, Z1>, F<X2, Y1, Z2>, F<X3, Y1, Z1>, F<X3, Y1, Z2>>>)); BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product<F3, L1, L2, L3>, std::tuple<F3<X1, Y1, Z1>, F3<X1, Y1, Z2>, F3<X2, Y1, Z1>, F3<X2, Y1, Z2>, F3<X3, Y1, Z1>, F3<X3, Y1, Z2>>>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product_q<mp_quote<F>, L1, L2, L3>, std::tuple<F<X1, Y1, Z1>, F<X1, Y1, Z2>, F<X2, Y1, Z1>, F<X2, Y1, Z2>, F<X3, Y1, Z1>, F<X3, Y1, Z2>>>)); BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product_q<mp_quote<F3>, L1, L2, L3>, std::tuple<F3<X1, Y1, Z1>, F3<X1, Y1, Z2>, F3<X2, Y1, Z1>, F3<X2, Y1, Z2>, F3<X3, Y1, Z1>, F3<X3, Y1, Z2>>>));
} }
{ {
@@ -49,8 +50,8 @@ int main()
using L2 = mp_list<>; using L2 = mp_list<>;
using L3 = std::pair<Z1, Z2>; using L3 = std::pair<Z1, Z2>;
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product<F, L1, L2, L3>, std::tuple<>>)); BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product<F3, L1, L2, L3>, std::tuple<>>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product_q<mp_quote<F>, L1, L2, L3>, std::tuple<>>)); BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product_q<mp_quote<F3>, L1, L2, L3>, std::tuple<>>));
} }
{ {
@@ -64,5 +65,10 @@ int main()
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product_q<mp_quote<F1>, L2>, mp_list<F1<X1>, F1<X2>, F1<X3>>>)); BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product_q<mp_quote<F1>, L2>, mp_list<F1<X1>, F1<X2>, F1<X3>>>));
} }
{
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product<F>, mp_list<F<>>>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_product_q<mp_quote<F>>, mp_list<F<>>>));
}
return boost::report_errors(); return boost::report_errors();
} }