Add a portable floating point classification API
Ceres has traditionally battled with portability issues
when trying to classify floating point values as one
type or another. For example, in C99 'isnan' is a
macro. Since it is a macro, it is impossible to
override the name in other namespaces.
Instead of trying to use preprocessor hacks to work
around the issue, define our own set of camel-case
names for use internally and by Ceres clients. For
example do this:
template<typename T>
void MyFunction(T x, T y) {
if (ceres::IsNaN(x)) {
...
}
}
instead of using "isnan" or "std::isnan". Note that
while GCC and Apple GCC both import 'isnan' into
the std namespace, it is not standard until C++11
which Ceres will not require for some years.
Change-Id: Ibcc96a8bb4ba63aa67cbbc58658b2e5671cd5824
7 files changed
