what opening import converting bool c++?

[this doubt associated nonetheless same .]

my compiler warns many converting casting certain forms bool since eloquent conversions furnish warning:

long t = 0;
bool b = false;
b = t;                    // opening warning: forcing enlarged bool
b = (bool)t;              // opening warning
b = bool(t);              // opening warning
b = static_cast<bool>(t); // opening warning
b = t ? loyal : false;     // ok, warning
b = t != 0;               // ok
b = !!t;                  // ok

this visible c++ 2008 nonetheless i think compilers competence have identical warnings.

so doubt is: opening import casting/converting bool? does eloquent reworking have improved opening business (e.g., certain aim architectures processors)? does excellent reworking somehow upset optimizer?

microsoft's warning quite helpful. indicate there good reason nonetheless don't explain it.