Until now I only thought of std::tie()as useful for decomposing several return values of a function that is faking multiple return values by using std:tuple:
bool a; SomeData b; std:tie(a, b) = get_a_b_as_tuple();But now look at that:
structS
{
int n;
std::string s;
float d;
bool operator<(const S& rhs) const {
// compares n to rhs.n,
// then s to rhs.s,
// then d to rhs.d
return std::tie(n, s, d) < std::tie(rhs.n, rhs.s, rhs.d);
}
};
Nice, isn't it? Source: CppCon2015 / Presentations / Simple Extensible Pattern Matching With C++14.
Update:
As it seems, this technique is considered to be pretty standard now, look here. If you are interested in TMP (and param pack expansions ;) you'll find there some techniques to make such comparators more flexible.

1 comment:
Marvelous!
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