diff options
Diffstat (limited to 'libbuild2/variable.txx')
| -rw-r--r-- | libbuild2/variable.txx | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/libbuild2/variable.txx b/libbuild2/variable.txx index 0b831e9..a1ee340 100644 --- a/libbuild2/variable.txx +++ b/libbuild2/variable.txx @@ -38,6 +38,11 @@ namespace build2 { if (v.type == nullptr) return convert<T> (move (v).as<names> ()); + // + // Note that while it may be tempting to use is_a() here like in cast(), + // the implications are unclear (i.e., we may end up relaxing things we + // don't want to). So we have the convert_to_base() variants instead. + // else if (v.type == &value_traits<T>::value_type) return move (v).as<T> (); } @@ -61,6 +66,36 @@ namespace build2 } template <typename T> + T + convert_to_base (value&& v) + { + if (v) + { + if (v.type == nullptr) + return convert<T> (move (v).as<names> ()); + else if (v.type->is_a<T> ()) + return move (v).as<T> (); + } + + convert_throw (v ? v.type : nullptr, value_traits<T>::value_type); + } + + template <typename T> + T + convert_to_base (const value& v) + { + if (v) + { + if (v.type == nullptr) + return convert<T> (names (v.as<names> ())); + else if (v.type->is_a<T> ()) + return v.as<T> (); + } + + convert_throw (v ? v.type : nullptr, value_traits<T>::value_type); + } + + template <typename T> void default_dtor (value& v) { |