diff options
Diffstat (limited to 'indra')
| -rw-r--r-- | indra/llcommon/llmake.h | 52 |
1 files changed, 28 insertions, 24 deletions
diff --git a/indra/llcommon/llmake.h b/indra/llcommon/llmake.h index 08744f90fb..02463d97ea 100644 --- a/indra/llcommon/llmake.h +++ b/indra/llcommon/llmake.h @@ -12,10 +12,8 @@ * * also relevant: * - * Template argument deduction for class templates - * http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0091r3.html - * was apparently adopted in June 2016? Unclear when compilers will - * portably support this, but there is hope. + * Template argument deduction for class templates (C++17) + * https://en.cppreference.com/w/cpp/language/class_template_argument_deduction * * $LicenseInfo:firstyear=2015&license=viewerlgpl$ * Copyright (c) 2015, Linden Research, Inc. @@ -25,37 +23,43 @@ #if ! defined(LL_LLMAKE_H) #define LL_LLMAKE_H -/*==========================================================================*| -// When we allow ourselves to compile with C++11 features enabled, this form -// should generically handle an arbitrary number of arguments. - +/** + * Usage: llmake<SomeTemplate>(args...) + * + * Deduces the types T... of 'args' and returns an instance of + * SomeTemplate<T...>(args...). + */ template <template<typename...> class CLASS_TEMPLATE, typename... ARGS> CLASS_TEMPLATE<ARGS...> llmake(ARGS && ... args) { return CLASS_TEMPLATE<ARGS...>(std::forward<ARGS>(args)...); } -|*==========================================================================*/ -// As of 2015-12-18, this is what we'll use instead. Add explicit overloads -// for different numbers of template parameters as use cases arise. +/// dumb pointer template just in case that's what's wanted +template <typename T> +using dumb_pointer = T*; /** - * Usage: llmake<SomeTemplate>(arg) + * Same as llmake(), but returns a pointer to a new heap instance of + * SomeTemplate<T...>(args...) using the pointer of your choice. * - * Deduces the type T of 'arg' and returns an instance of SomeTemplate<T> - * initialized with 'arg'. Assumes a constructor accepting T (by value, - * reference or whatever). + * @code + * auto* dumb = llmake_heap<SomeTemplate>(args...); + * auto shared = llmake_heap<SomeTemplate, std::shared_ptr>(args...); + * auto unique = llmake_heap<SomeTemplate, std::unique_ptr>(args...); + * @endcode */ -template <template<typename> class CLASS_TEMPLATE, typename ARG1> -CLASS_TEMPLATE<ARG1> llmake(const ARG1& arg1) -{ - return CLASS_TEMPLATE<ARG1>(arg1); -} - -template <template<typename, typename> class CLASS_TEMPLATE, typename ARG1, typename ARG2> -CLASS_TEMPLATE<ARG1, ARG2> llmake(const ARG1& arg1, const ARG2& arg2) +// POINTER_TEMPLATE is characterized as template<typename...> rather than as +// template<typename T> because (e.g.) std::unique_ptr has multiple template +// arguments. Even though we only engage one, std::unique_ptr doesn't match a +// template template parameter that itself takes only one template parameter. +template <template<typename...> class CLASS_TEMPLATE, + template<typename...> class POINTER_TEMPLATE=dumb_pointer, + typename... ARGS> +POINTER_TEMPLATE<CLASS_TEMPLATE<ARGS...>> llmake_heap(ARGS&&... args) { - return CLASS_TEMPLATE<ARG1, ARG2>(arg1, arg2); + return POINTER_TEMPLATE<CLASS_TEMPLATE<ARGS...>>( + new CLASS_TEMPLATE<ARGS...>(std::forward<ARGS>(args)...)); } #endif /* ! defined(LL_LLMAKE_H) */ |