diff options
Diffstat (limited to 'bpkg/wrapper-traits')
-rw-r--r-- | bpkg/wrapper-traits | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/bpkg/wrapper-traits b/bpkg/wrapper-traits new file mode 100644 index 0000000..add28e8 --- /dev/null +++ b/bpkg/wrapper-traits @@ -0,0 +1,59 @@ +// file : bpkg/wrapper-traits -*- C++ -*- +// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd +// license : MIT; see accompanying LICENSE file + +#ifndef BPKG_WRAPPER_TRAITS +#define BPKG_WRAPPER_TRAITS + +#include <butl/optional> + +#include <odb/wrapper-traits.hxx> + +namespace odb +{ + template <typename T> + class wrapper_traits<butl::optional<T>> + { + public: + typedef T wrapped_type; + typedef butl::optional<T> wrapper_type; + + // T can be const. + // + typedef + typename odb::details::meta::remove_const<T>::result + unrestricted_wrapped_type; + + static const bool null_handler = true; + static const bool null_default = true; + + static bool + get_null (const wrapper_type& o) + { + return !o; + } + + static void + set_null (wrapper_type& o) + { + o = wrapper_type (); + } + + static const wrapped_type& + get_ref (const wrapper_type& o) + { + return *o; + } + + static unrestricted_wrapped_type& + set_ref (wrapper_type& o) + { + if (!o) + o = unrestricted_wrapped_type (); + + return const_cast<unrestricted_wrapped_type&> (*o); + } + }; +} + +#endif // BPKG_WRAPPER_TRAITS |