Add missing erase(first, last) function to ordered_map (#3109)
This commit is contained in:
Niels Lohmann
GitHub
parent
834918018e
commit
e9f88c2fad
@ -107,16 +107,55 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
|
||||
|
||||
iterator erase(iterator pos)
|
||||
{
|
||||
auto it = pos;
|
||||
return erase(pos, std::next(pos));
|
||||
}
|
||||
|
||||
// Since we cannot move const Keys, re-construct them in place
|
||||
for (auto next = it; ++next != this->end(); ++it)
|
||||
iterator erase(iterator first, iterator last)
|
||||
{
|
||||
const auto elements_affected = std::distance(first, last);
|
||||
const auto offset = std::distance(Container::begin(), first);
|
||||
|
||||
// This is the start situation. We need to delete elements_affected
|
||||
// elements (3 in this example: e, f, g), and need to return an
|
||||
// iterator past the last deleted element (h in this example).
|
||||
// Note that offset is the distance from the start of the vector
|
||||
// to first. We will need this later.
|
||||
|
||||
// [ a, b, c, d, e, f, g, h, i, j ]
|
||||
// ^ ^
|
||||
// first last
|
||||
|
||||
// Since we cannot move const Keys, we re-construct them in place.
|
||||
// We start at first and re-construct (viz. copy) the elements from
|
||||
// the back of the vector. Example for first iteration:
|
||||
|
||||
// ,--------.
|
||||
// v | destroy e and re-construct with h
|
||||
// [ a, b, c, d, e, f, g, h, i, j ]
|
||||
// ^ ^
|
||||
// it it + elements_affected
|
||||
|
||||
for (auto it = first; std::next(it, elements_affected) != Container::end(); ++it)
|
||||
{
|
||||
it->~value_type(); // Destroy but keep allocation
|
||||
new (&*it) value_type{std::move(*next)};
|
||||
it->~value_type(); // destroy but keep allocation
|
||||
new (&*it) value_type{std::move(*std::next(it, elements_affected))}; // "move" next element to it
|
||||
}
|
||||
Container::pop_back();
|
||||
return pos;
|
||||
|
||||
// [ a, b, c, d, h, i, j, h, i, j ]
|
||||
// ^ ^
|
||||
// first last
|
||||
|
||||
// remove the unneeded elements at the end of the vector
|
||||
Container::resize(this->size() - static_cast<size_type>(elements_affected));
|
||||
|
||||
// [ a, b, c, d, h, i, j ]
|
||||
// ^ ^
|
||||
// first last
|
||||
|
||||
// first is now pointing past the last deleted element, but we cannot
|
||||
// use this iterator, because it may have been invalidated by the
|
||||
// resize call. Instead, we can return begin() + offset.
|
||||
return Container::begin() + offset;
|
||||
}
|
||||
|
||||
size_type count(const Key& key) const
|
||||
|
||||
@ -17494,16 +17494,55 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
|
||||
|
||||
iterator erase(iterator pos)
|
||||
{
|
||||
auto it = pos;
|
||||
return erase(pos, std::next(pos));
|
||||
}
|
||||
|
||||
// Since we cannot move const Keys, re-construct them in place
|
||||
for (auto next = it; ++next != this->end(); ++it)
|
||||
iterator erase(iterator first, iterator last)
|
||||
{
|
||||
const auto elements_affected = std::distance(first, last);
|
||||
const auto offset = std::distance(Container::begin(), first);
|
||||
|
||||
// This is the start situation. We need to delete elements_affected
|
||||
// elements (3 in this example: e, f, g), and need to return an
|
||||
// iterator past the last deleted element (h in this example).
|
||||
// Note that offset is the distance from the start of the vector
|
||||
// to first. We will need this later.
|
||||
|
||||
// [ a, b, c, d, e, f, g, h, i, j ]
|
||||
// ^ ^
|
||||
// first last
|
||||
|
||||
// Since we cannot move const Keys, we re-construct them in place.
|
||||
// We start at first and re-construct (viz. copy) the elements from
|
||||
// the back of the vector. Example for first iteration:
|
||||
|
||||
// ,--------.
|
||||
// v | destroy e and re-construct with h
|
||||
// [ a, b, c, d, e, f, g, h, i, j ]
|
||||
// ^ ^
|
||||
// it it + elements_affected
|
||||
|
||||
for (auto it = first; std::next(it, elements_affected) != Container::end(); ++it)
|
||||
{
|
||||
it->~value_type(); // Destroy but keep allocation
|
||||
new (&*it) value_type{std::move(*next)};
|
||||
it->~value_type(); // destroy but keep allocation
|
||||
new (&*it) value_type{std::move(*std::next(it, elements_affected))}; // "move" next element to it
|
||||
}
|
||||
Container::pop_back();
|
||||
return pos;
|
||||
|
||||
// [ a, b, c, d, h, i, j, h, i, j ]
|
||||
// ^ ^
|
||||
// first last
|
||||
|
||||
// remove the unneeded elements at the end of the vector
|
||||
Container::resize(this->size() - static_cast<size_type>(elements_affected));
|
||||
|
||||
// [ a, b, c, d, h, i, j ]
|
||||
// ^ ^
|
||||
// first last
|
||||
|
||||
// first is now pointing past the last deleted element, but we cannot
|
||||
// use this iterator, because it may have been invalidated by the
|
||||
// resize call. Instead, we can return begin() + offset.
|
||||
return Container::begin() + offset;
|
||||
}
|
||||
|
||||
size_type count(const Key& key) const
|
||||
|
||||
@ -210,6 +210,45 @@ TEST_CASE("ordered_map")
|
||||
++it2;
|
||||
CHECK(it2 == om.end());
|
||||
}
|
||||
|
||||
SECTION("with iterator pair")
|
||||
{
|
||||
SECTION("range in the middle")
|
||||
{
|
||||
// need more elements
|
||||
om["vier"] = "four";
|
||||
om["fünf"] = "five";
|
||||
|
||||
// delete "zwei" and "drei"
|
||||
auto it = om.erase(om.begin() + 1, om.begin() + 3);
|
||||
CHECK(it->first == "vier");
|
||||
CHECK(om.size() == 3);
|
||||
}
|
||||
|
||||
SECTION("range at the beginning")
|
||||
{
|
||||
// need more elements
|
||||
om["vier"] = "four";
|
||||
om["fünf"] = "five";
|
||||
|
||||
// delete "eins" and "zwei"
|
||||
auto it = om.erase(om.begin(), om.begin() + 2);
|
||||
CHECK(it->first == "drei");
|
||||
CHECK(om.size() == 3);
|
||||
}
|
||||
|
||||
SECTION("range at the end")
|
||||
{
|
||||
// need more elements
|
||||
om["vier"] = "four";
|
||||
om["fünf"] = "five";
|
||||
|
||||
// delete "vier" and "fünf"
|
||||
auto it = om.erase(om.begin() + 3, om.end());
|
||||
CHECK(it == om.end());
|
||||
CHECK(om.size() == 3);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
SECTION("count")
|
||||
|
||||
@ -746,6 +746,23 @@ TEST_CASE("regression tests 2")
|
||||
std::vector<FooBar> foo;
|
||||
j.get_to(foo);
|
||||
}
|
||||
|
||||
SECTION("issue #3108 - ordered_json doesn't support range based erase")
|
||||
{
|
||||
ordered_json j = {1, 2, 2, 4};
|
||||
|
||||
auto last = std::unique(j.begin(), j.end());
|
||||
j.erase(last, j.end());
|
||||
|
||||
CHECK(j.dump() == "[1,2,4]");
|
||||
|
||||
j.erase(std::remove_if(j.begin(), j.end(), [](const ordered_json & val)
|
||||
{
|
||||
return val == 2;
|
||||
}), j.end());
|
||||
|
||||
CHECK(j.dump() == "[1,4]");
|
||||
}
|
||||
}
|
||||
|
||||
DOCTEST_CLANG_SUPPRESS_WARNING_POP
|
||||
|
||||
Loading…
Reference in New Issue
Block a user