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[Map] Provide model of Foldable, improve docs and add insert method.

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Fixes #41
This commit is contained in:
Louis Dionne
2015-04-11 10:38:52 -04:00
parent 8bd84a5d4b
commit daaba5dfd8
11 changed files with 701 additions and 385 deletions
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114
example/map.cpp
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@@ -6,10 +6,12 @@ Distributed under the Boost Software License, Version 1.0.
#include <boost/hana/assert.hpp>
#include <boost/hana/config.hpp>
#include <boost/hana/functional/placeholder.hpp>
#include <boost/hana/integral_constant.hpp>
#include <boost/hana/map.hpp>
#include <boost/hana/maybe.hpp>
#include <boost/hana/pair.hpp>
#include <boost/hana/set.hpp>
#include <boost/hana/type.hpp>
#include <string>
@@ -22,6 +24,7 @@ int main() {
//! [make<Map>]
using namespace std::literals;
auto m = make<Map>(
make<Pair>(int_<1>, "foobar"s),
make<Pair>(type<void>, 1234)
@@ -33,6 +36,7 @@ auto m = make<Map>(
//! [make_map]
using namespace std::literals;
BOOST_HANA_RUNTIME_CHECK(
make_map(
make<Pair>(int_<1>, "foobar"s),
@@ -48,8 +52,76 @@ BOOST_HANA_RUNTIME_CHECK(
}{
//! [comparable]
//! [values]
using namespace std::literals;
auto m = make<Map>(
make<Pair>(int_<1>, "foobar"s),
make<Pair>(type<void>, 1234)
);
// The order of the values is unspecified.
BOOST_HANA_RUNTIME_CHECK(values(m) ^in^ permutations(make<Tuple>("foobar"s, 1234)));
//! [values]
}{
//! [keys]
using namespace std::literals;
auto m = make<Map>(
make<Pair>(int_<1>, "foobar"s),
make<Pair>(type<void>, 1234)
);
// The order of the keys is unspecified.
BOOST_HANA_CONSTANT_CHECK(keys(m) ^in^ permutations(make<Tuple>(int_<1>, type<void>)));
//! [keys]
}{
//! [from_Foldable]
using namespace std::literals;
BOOST_HANA_RUNTIME_CHECK(
to<Map>(make<Tuple>(
make<Pair>(type<int>, "abcd"s),
make<Pair>(type<void>, 1234),
make<Pair>(type<int>, nullptr)
)) == make<Map>(
make<Pair>(type<int>, "abcd"s),
make<Pair>(type<void>, 1234)
)
);
//! [from_Foldable]
}{
//! [insert]
using namespace std::literals;
auto m = make<Map>(
make<Pair>(type<int>, "abcd"s),
make<Pair>(type<void>, 1234)
);
BOOST_HANA_RUNTIME_CHECK(
insert(m, make<Pair>(type<float>, 'x')) ==
make<Map>(
make<Pair>(type<int>, "abcd"s),
make<Pair>(type<void>, 1234),
make<Pair>(type<float>, 'x')
)
);
BOOST_HANA_RUNTIME_CHECK(insert(m, make<Pair>(type<void>, 'x')) == m);
//! [insert]
}{
//! [Comparable]
using namespace std::literals;
BOOST_HANA_RUNTIME_CHECK(
make_map(
make_pair(char_<'a'>, "foobar"s),
@@ -61,20 +133,48 @@ BOOST_HANA_RUNTIME_CHECK(
make_pair(char_<'a'>, "foobar"s)
)
);
//! [comparable]
//! [Comparable]
}{
//! [searchable]
BOOST_HANA_CONSTEXPR_LAMBDA auto m = make_map(
//! [Searchable]
constexpr auto m = make_map(
make_pair(type<int>, 'i'),
make_pair(type<float>, 'f')
);
BOOST_HANA_CONSTEXPR_CHECK(find(m, type<int>) == just('i'));
BOOST_HANA_CONSTEXPR_CHECK(find(m, type<float>) == just('f'));
static_assert(find(m, type<int>) == just('i'), "");
static_assert(find(m, type<float>) == just('f'), "");
BOOST_HANA_CONSTANT_CHECK(find(m, type<void>) == nothing);
BOOST_HANA_CONSTANT_CHECK(find(m, int_<3>) == nothing);
//! [searchable]
//! [Searchable]
}{
//! [Foldable]
using namespace std::literals;
// Given a map of (key, value) pairs, returns a map of (value, key) pairs.
// This requires both the keys and the values to be compile-time Comparable.
auto invert = [](auto map) {
return fold.left(map, make_map(), [](auto map, auto pair) {
return insert(map, make_pair(second(pair), first(pair)));
});
};
auto m = make_map(
make_pair(type<int>, int_<1>),
make_pair(type<float>, int_<2>),
make_pair(int_<3>, type<void>)
);
BOOST_HANA_CONSTANT_CHECK(invert(m) ==
make_map(
make_pair(int_<1>, type<int>),
make_pair(int_<2>, type<float>),
make_pair(type<void>, int_<3>)
)
);
//! [Foldable]
}