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// quote from cppreference.com:
// std::reference_wrapper is a class template that wraps a reference
// in a copyable, assignable object. It is frequently used as a mechanism
// to store references inside standard containers (like std::vector)
// which cannot normally hold references.
#include <cybozu/test.hpp>
#include <functional>
#include <iostream>
#include <vector>
struct foo {
int i;
};
AUTOTEST(intref) {
int *p = nullptr;
std::reference_wrapper<int> a[3] = {*p, *p, *p};
int i = 3;
a[0] = std::ref(i);
cybozu_assert( &(a[2].get()) == nullptr );
a[0].get() = 5;
cybozu_assert( i == 5 );
}
AUTOTEST(structref) {
foo f;
f.i = 3;
std::vector<std::reference_wrapper<const foo>> v;
v.emplace_back(f);
cybozu_assert( v[0].get().i == 3 );
f.i = 5;
cybozu_assert( v[0].get().i == 5 );
}
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