Re: [Boost-users] find the largest/most precise of two types

20 May 2009

      AMDG

Alex Flint wrote:
...
I have a bunch of functions that accept two numeric arguments. In the
case that the types of these arguments are different I want to figure
out what the return type should be. The rule I would like to use is
that the largest of the two types should be used for internal
computations and the return type.
f(someFloat, someDouble) -> double
f(someFloat, someFloat) -> float
f(someInt, someFloat) -> float
Is there a way I can do this, perhaps with boost's type_traits?
A quick glance through type_traits didn't show anything.

How does this work:

#include 

template
struct promote {
    BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (T0() + T1()))
    typedef typename nested::type type;
};

In Christ,
Steven Watanabe