folly::compiler_may_unsafely_assume_unreachable

[[noreturn]]
void
compiler_may_unsafely_assume_unreachable();

Description

Unsafe. Avoid when not absolutely necessary.

Permits the compiler to assume that the given statement cannot be reached and to optimize the surrounding code accordingly. Permits call sites to omit return statements in non-void-returning functions without compiler error.

Causes every possible kind of subtle, irreproducible, non-debuggable failure if the given statement is ever, for any reason, reached: random crashes, silent memory corruptions, arbitrary code execution, privacy violation, etc.

Must only be used on conditions that are provable internal logic invariants.

Must not be used on conditions which depend on external inputs. For such cases, an assertion or exception may be used instead.