| | 1 | ///////////////////////////////////////////////////////////////////////////// |
| | 2 | // Name: wx/meta/convertible.h |
| | 3 | // Purpose: Test if types are convertible |
| | 4 | // Author: Arne Steinarson |
| | 5 | // Created: 2008-01-10 |
| | 6 | // RCS-ID: $Id$ |
| | 7 | // Copyright: (c) 2008 Arne Steinarson |
| | 8 | // Licence: wxWindows licence |
| | 9 | ///////////////////////////////////////////////////////////////////////////// |
| | 10 | |
| | 11 | #ifndef _WX_META_CONVERTIBLE_H_ |
| | 12 | #define _WX_META_CONVERTIBLE_H_ |
| | 13 | |
| | 14 | // |
| | 15 | // Introduce an extra class to make this header compilable with g++3.2 |
| | 16 | // |
| | 17 | template <class D, class B> |
| | 18 | struct wxConvertibleTo_SizeHelper |
| | 19 | { |
| | 20 | static char Match(B* pb); |
| | 21 | static int Match(...); |
| | 22 | }; |
| | 23 | |
| | 24 | // Helper to decide if an object of type D is convertible to type B (the test |
| | 25 | // succeeds in particular when D derives from B) |
| | 26 | template <class D, class B> |
| | 27 | struct wxConvertibleTo |
| | 28 | { |
| | 29 | enum |
| | 30 | { |
| | 31 | value = |
| | 32 | sizeof(wxConvertibleTo_SizeHelper<D,B>::Match(static_cast<D*>(NULL))) |
| | 33 | == |
| | 34 | sizeof(char) |
| | 35 | }; |
| | 36 | }; |
| | 37 | |
| | 38 | #endif // _WX_META_CONVERTIBLE_H_ |
| | 39 | |
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