What are use cases for structured bindings?

Question

C++17 standard introduces a new structured bindings feature, which was initially proposed in 2015 and whose syntactic appearance was widely discussed later.

Some use

Answer 1

Barring evidence to the contrary, I think Structured Bindings are merely a vehicle to deal with legacy API. IMHO, the APIs which require SB should have been fixed instead.

So, instead of

auto p = map.equal_range(k);
for (auto it = p.first; it != p.second; ++it)
    doSomethingWith(it->first, it->second);

we should be able to write

for (auto &e : map.equal_range(k))
    doSomethingWith(e.key, e.value);

Instead of

auto r = map.insert({k, v});
if (!r.second)
    *r.first = v;

we should be able to write

auto r = map.insert({k, v});
if (!r)
    r = v;

etc.

Sure, someone will find a clever use at some point, but to me, after a year of knowing about them, they are still an unsolved mystery. Esp. since the paper is co-authored by Bjarne, who's not usually known for introducing features that have such a narrow applicability.