bugprone-unchecked-optional-access false positive

[moar55]

For the following snippet using std::optional monadic operations:

struct S {
  std::optional<int> a;
  std::string b;
}

void test(std::optional<S> s) {
   if (s.and_then(&S::a).has_value()) {
       std::cout << "The value is " << *s->a << std::endl;
   }
}

I get this clang-tidy warning:

unchecked access to optional value [bugprone-unchecked-optional-access]

             123 TestOptional(std::optional<S> s)
             124 {
             125   if (s.and_then(&S::a).has_value()) {
    >>>      126     std::cout << "The value is " << *s->a << std::endl;
             127   }
             128 }

This is a false positive since i do check that s, and subsequently its member a, has values, yet I get bugprone-unchecked-optional-access warning on the de-referencing of s and a.

Is this something feasible to support? Also, is it worth the effort, since we wouldn't be fully supporting emulating any lambda within the and_then, but just projections?

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: Omar Hossam (moar55)

For the following snippet using std::optional monadic operations: ```cpp struct S { std::optional<int> a; std::string b; }

void test(std::optional<S> s) {
if (s.and_then(&S::a).has_value()) {
std::cout << "The value is " << *s->a << std::endl;
}
}

I get this clang-tidy warning:

unchecked access to optional value [bugprone-unchecked-optional-access]

         123 TestOptional(std::optional<S> s)
         124 {
         125   if (s.and_then(&S::a).has_value()) {
>>>      126     std::cout << "The value is " << *s->a << std::endl;
         127   }
         128 }

This is a false positive since i do check that `s`, and subsequently its member `a`, has values, yet I get `bugprone-unchecked-optional-access` warning on the de-referencing of `s` and `a`.

Is this something feasible to support? Also,  is it worth the effort, since we wouldn't be fully supporting emulating any lambda within the `and_then`, but just projections?
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