template <typename typea, typename typeb>bool Is_A_GT_B(typea a, typeb b){ bool isASigned = std::numeric_limits<typea>::is_signed; bool isBSigned = std::numeric_limits<typeb>::is_signed; if(isASigned != isBSigned && (isASigned ? a : b) < 0) return isBSigned; return a > b;}which is larger?
That looks right. Though the sadist in me wants to write:
Author
Thanks for the discussion.
The signedness checks can be done statically to improve upon efficiency:
The signedness checks can be done statically to improve upon efficiency:
template <class A, class B, bool ASigned, bool BSigned>struct greater_impl{ static inline bool call(A a, B b) { return a > b; }};template <class A, class B>struct greater_impl<A, B, true, false>{ static inline bool call(A a, B b) { if( a < 0 ) return false; return a > b; }};template <class A, class B>struct greater_impl<A, B, false, true>{ static inline bool call(A a, B b) { if( b < 0 ) return true; return a > b; }};template<class A, class B>inline bool safe_greater(A a, B b){ return greater_impl<A,B, std::numeric_limits<A>::is_signed, std::numeric_limits<B>::is_signed >::call(a,b);}
Because the is_signed field is a static const, there's no need to use template specialization here -- any sane compiler will remove the static branch automatically.
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