diff options
author | Michael Shepanski <michael@codesynthesis.com> | 2014-11-04 16:10:03 +1100 |
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committer | Boris Kolpackov <boris@codesynthesis.com> | 2014-11-10 16:43:00 +0200 |
commit | 6375147d5ae76a84dd64f1996cb0d9d501839db6 (patch) | |
tree | 1240e3b8c1567fde1ae11d0c93e5b38c15111506 /odb/result.txx | |
parent | 1f217e38f7507758da1d33d46e675e801621aa38 (diff) |
Implement {query,execute}_{one,value}() shortcut functions
Useful in situations where the query is know to return at most one element
(*_one) or exactly one element (*_value).
Diffstat (limited to 'odb/result.txx')
-rw-r--r-- | odb/result.txx | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/odb/result.txx b/odb/result.txx new file mode 100644 index 0000000..c1bed1c --- /dev/null +++ b/odb/result.txx @@ -0,0 +1,52 @@ +// file : odb/result.txx +// copyright : Copyright (c) 2009-2013 Code Synthesis Tools CC +// license : GNU GPL v2; see accompanying LICENSE file + +#include <cassert> + +namespace odb +{ + template <typename T> + typename object_traits<T>::pointer_type result<T>:: + one () + { + typedef typename object_traits<T>::pointer_type pointer_type; + + iterator i (begin ()); + + if (i != end ()) + { + pointer_type o (i.load ()); + assert (++i == end ()); // More than one element in query_one() result. + return o; + } + + return pointer_type (); + } + + template <typename T> + bool result<T>:: + one (T& o) + { + iterator i (begin ()); + + if (i != end ()) + { + i.load (o); + assert (++i == end ()); // More than one element in query_one() result. + return true; + } + + return false; + } + + template <typename T> + void result<T>:: + value (T& o) + { + iterator i (begin ()); + assert (i != end ()); // Zero elements in query_value() result. + i.load (o); + assert (++i == end ()); // More than one element in query_value() result. + } +} |