llvm-project/libcxx/test/std/containers/unord/unord.set/rehash.pass.cpp

105 lines
2.6 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <unordered_set>
// template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
// class Alloc = allocator<Value>>
// class unordered_set
// void rehash(size_type n);
#include <unordered_set>
#include <cassert>
#include "test_macros.h"
#include "min_allocator.h"
template <class C>
void rehash_postcondition(const C& c, size_t n)
{
assert(c.bucket_count() >= c.size() / c.max_load_factor() && c.bucket_count() >= n);
}
template <class C>
void test(const C& c)
{
assert(c.size() == 4);
assert(c.count(1) == 1);
assert(c.count(2) == 1);
assert(c.count(3) == 1);
assert(c.count(4) == 1);
}
int main(int, char**)
{
{
typedef std::unordered_set<int> C;
typedef int P;
P a[] =
{
P(1),
P(2),
P(3),
P(4),
P(1),
P(2)
};
C c(a, a + sizeof(a)/sizeof(a[0]));
test(c);
assert(c.bucket_count() >= 5);
c.rehash(3);
rehash_postcondition(c, 3);
LIBCPP_ASSERT(c.bucket_count() == 5);
test(c);
c.max_load_factor(2);
c.rehash(3);
rehash_postcondition(c, 3);
LIBCPP_ASSERT(c.bucket_count() == 3);
test(c);
c.rehash(31);
rehash_postcondition(c, 31);
LIBCPP_ASSERT(c.bucket_count() == 31);
test(c);
}
#if TEST_STD_VER >= 11
{
typedef std::unordered_set<int, std::hash<int>,
std::equal_to<int>, min_allocator<int>> C;
typedef int P;
P a[] =
{
P(1),
P(2),
P(3),
P(4),
P(1),
P(2)
};
C c(a, a + sizeof(a)/sizeof(a[0]));
test(c);
assert(c.bucket_count() >= 5);
c.rehash(3);
rehash_postcondition(c, 3);
LIBCPP_ASSERT(c.bucket_count() == 5);
test(c);
c.max_load_factor(2);
c.rehash(3);
rehash_postcondition(c, 3);
LIBCPP_ASSERT(c.bucket_count() == 3);
test(c);
c.rehash(31);
rehash_postcondition(c, 31);
LIBCPP_ASSERT(c.bucket_count() == 31);
test(c);
}
#endif
return 0;
}