[jfkebwjsbx]

If you use only explicit constructors and ban cast operators except for the most basic of types, then you have a sane language and explicitness in your code.

[MaxBarraclough]

Sounds sensible. Google seems to agree with you. https://google.github.io/styleguide/cppguide.html#Implicit_C...

LLVM's coding standard though doesn't seem to have anything to say about implicit conversions: https://llvm.org/docs/CodingStandards.html

[GoblinSlayer]

It's sane on C++ scale, but on absolute scale that sanity is still wanting, Sutter mentions this.