diff options
| -rw-r--r-- | project2/common/options.h | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/project2/common/options.h b/project2/common/options.h index b4cbaf8..2ccb7ec 100644 --- a/project2/common/options.h +++ b/project2/common/options.h @@ -7,6 +7,27 @@ #include <list> #include <boost/lexical_cast.hpp> +namespace std { + // + // Should be part of the standard headers, but seems to be missing + // + template<typename _Tp, typename _Up> + class __is_assignable_helper : public __sfinae_types { + template<typename _Tp1, typename _Up1> + static decltype(declval<_Tp1>() = declval<_Up1>(), __one()) __test(int); + + template<typename, typename> + static __two __test(...); + + public: + static constexpr bool value = sizeof(__test<_Tp, _Up>(0)) == 1; + }; + /// is_assignable + template<typename _Tp, typename _Up> + struct is_assignable : public integral_constant<bool, __is_assignable_helper<_Tp, _Up>::value> + { }; +} + class Options { public: class Target; @@ -43,10 +64,19 @@ class Options { *target = T(); } void assign(const Glib::ustring & value) const { - *target = boost::lexical_cast<T>(value); + doAssign(value); } protected: T * target; + private: + template <typename dummy = int> + void doAssign(const Glib::ustring & value, typename boost::disable_if<std::is_assignable<T, Glib::ustring>, dummy>::type = 0) const { + *target = boost::lexical_cast<T>(value); + } + template <typename dummy = int> + void doAssign(const Glib::ustring & value, typename boost::enable_if<std::is_assignable<T, Glib::ustring>, dummy>::type = 0) const { + *target = value; + } }; template <typename T> class TypedTarget<std::vector<T> > : public InstanceTarget { @@ -66,9 +96,9 @@ class Options { VofT * target; }; - template <typename T> class DefaultTypedTarget : public TypedTarget<T> { + template <typename T, typename D> class DefaultTypedTarget : public TypedTarget<T> { public: - DefaultTypedTarget(T * t, const T & d) : + DefaultTypedTarget(T * t, const D & d) : TypedTarget<T>(t), defValue(d) { } @@ -104,7 +134,7 @@ class Options { template <typename T, typename D> static TargetPtr value(T * t, const D & d) { - return new DefaultTypedTarget<T>(t, d); + return new DefaultTypedTarget<T, D>(t, d); } void reset() const; |