implicit_cast<> only performs a cast in cases where an implicit
conversion would be possible. It’s even safer than static_cast<> It’s an
“explicit implicit” cast, which is not normally necsesary, but is
frequently required when working with the ?: operator, functions like
std::min() and std::max(), and logging and testing macros.
The public style guide does not mention implicit_cast<> only because it
is not part of the standard library, but would otherwise require it in
these situations. Since base does provide implicit_cast<>, it should be
used whenever possible.
The only uses of static_cast<> not converted to implicit_cast<> are
those that require static_cast<>, such as those that assign an integer
constant to a variable of an enum type.
R=rsesek@chromium.org
Review URL: https://codereview.chromium.org/700383007
InRangeCast<> is similar to base::saturated_cast<>, but it allows the
caller to specify the value to be returned in the event that the source
value can’t be converted to the destination data type without data loss.
TEST=util_test InRangeCast
R=rsesek@chromium.org
Review URL: https://codereview.chromium.org/467103002
