diff options
Diffstat (limited to 'libbuild2/target.hxx')
| -rw-r--r-- | libbuild2/target.hxx | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/libbuild2/target.hxx b/libbuild2/target.hxx index 0d4eece..20cd32d 100644 --- a/libbuild2/target.hxx +++ b/libbuild2/target.hxx @@ -1219,13 +1219,28 @@ namespace build2 } template <typename T> - typename std::enable_if<!data_invocable<T>::value, T&>::type& + typename std::enable_if<!data_invocable<T>::value, T&>::type data (action a) const { using V = typename std::remove_cv<T>::type; return state[a].recipe.target<data_wrapper<V>> ()->d; } + // Return NULL if there is no data or the data is of a different type. + // + template <typename T> + typename std::enable_if<!data_invocable<T>::value, T*>::type + try_data (action a) const + { + using V = typename std::remove_cv<T>::type; + + if (auto& r = state[a].recipe) + if (auto* t = r.target<data_wrapper<V>> ()) + return &t->d; + + return nullptr; + } + // Note that in this case we don't strip const (the expectation is that we // move the recipe in/out of data). // @@ -1250,12 +1265,20 @@ namespace build2 } template <typename T> - typename std::enable_if<data_invocable<T>::value, T&>::type& + typename std::enable_if<data_invocable<T>::value, T&>::type data (action a) const { return *state[a].recipe.target<T> (); } + template <typename T> + typename std::enable_if<data_invocable<T>::value, T*>::type + try_data (action a) const + { + auto& r = state[a].recipe; + return r ? r.target<T> () : nullptr; + } + // Target type info and casting. // public: |