libcxx/test/std/containers/unord/unord.set/load_factor.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <unordered_set>
  10
  11 // template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
  12 //           class Alloc = allocator<Value>>
  13 // class unordered_set
  14
  15 // float load_factor() const
  16
  17 #include <unordered_set>
  18 #include <cassert>
  19 #include <cfloat>
  20 #include <cmath>
  21
  22 #include "test_macros.h"
  23 #include "min_allocator.h"
  24
  25 int main(int, char**)
  26 {
  27     {
  28         typedef std::unordered_set<int> C;
  29         typedef int P;
  30         P a[] =
  31         {
  32             P(10),
  33             P(20),
  34             P(30),
  35             P(40),
  36             P(50),
  37             P(60),
  38             P(70),
  39             P(80)
  40         };
  41         const C c(std::begin(a), std::end(a));
  42         assert(std::fabs(c.load_factor() - (float)c.size()/c.bucket_count()) < FLT_EPSILON);
  43     }
  44     {
  45         typedef std::unordered_set<int> C;
  46         const C c;
  47         assert(c.load_factor() == 0);
  48     }
  49 #if TEST_STD_VER >= 11
  50     {
  51         typedef std::unordered_set<int, std::hash<int>,
  52                                       std::equal_to<int>, min_allocator<int>> C;
  53         typedef int P;
  54         P a[] =
  55         {
  56             P(10),
  57             P(20),
  58             P(30),
  59             P(40),
  60             P(50),
  61             P(60),
  62             P(70),
  63             P(80)
  64         };
  65         const C c(std::begin(a), std::end(a));
  66         assert(std::fabs(c.load_factor() - (float)c.size()/c.bucket_count()) < FLT_EPSILON);
  67     }
  68     {
  69         typedef std::unordered_set<int, std::hash<int>,
  70                                       std::equal_to<int>, min_allocator<int>> C;
  71         const C c;
  72         assert(c.load_factor() == 0);
  73     }
  74 #endif
  75
  76   return 0;
  77 }