diff options
Diffstat (limited to 'libbuild2/variable.hxx')
| -rw-r--r-- | libbuild2/variable.hxx | 122 |
1 files changed, 91 insertions, 31 deletions
diff --git a/libbuild2/variable.hxx b/libbuild2/variable.hxx index a671978..a9dde7f 100644 --- a/libbuild2/variable.hxx +++ b/libbuild2/variable.hxx @@ -610,6 +610,9 @@ namespace build2 // static const build2::value_type value_type; // }; + template <typename T> + struct value_traits<const T>: value_traits<T> {}; + // Convert name to a simple value. Throw invalid_argument (with a message) // if the name is not a valid representation of value (in which case the // name remains unchanged for diagnostics). The second version is called for @@ -897,6 +900,9 @@ namespace build2 // half of a pair). If both are empty then this is an empty value (and not a // pair of two empties). // + // @@ Maybe we should redo this with optional<> to signify which half can + // be missing? + // template <> struct LIBBUILD2_SYMEXPORT value_traits<name_pair> { @@ -1004,9 +1010,67 @@ namespace build2 static const build2::value_type value_type; }; + // optional<T> + // + // This is an incomplete implementation meant to provide enough support only + // to be usable as elements of containers. + // + template <typename T> + struct value_traits<optional<T>> + { + static int compare (const optional<T>&, const optional<T>&); + }; + + // pair<F, S> + // + // Either F or S can be optional<T> making the corresponding half of the + // pair optional. + // + // This is an incomplete implementation meant to provide enough support only + // to be usable as elements of containers. + // + template <typename F, typename S> + struct pair_value_traits + { + static pair<F, S> + convert (name&&, name*, const char*, const char*, const variable*); + + static void + reverse (const F&, const S&, names&); + }; + + template <typename F, typename S> + struct pair_value_traits<F, optional<S>> + { + static pair<F, optional<S>> + convert (name&&, name*, const char*, const char*, const variable*); + + static void + reverse (const F&, const optional<S>&, names&); + }; + + template <typename F, typename S> + struct pair_value_traits<optional<F>, S> + { + static pair<optional<F>, S> + convert (name&&, name*, const char*, const char*, const variable*); + + static void + reverse (const optional<F>&, const S&, names&); + }; + + template <typename F, typename S> + struct value_traits<pair<F, S>>: pair_value_traits<F, S> + { + static int compare (const pair<F, S>&, const pair<F, S>&); + }; + // vector<T> // template <typename T> + struct vector_value_type; + + template <typename T> struct value_traits<vector<T>> { static_assert (sizeof (vector<T>) <= value::size_, "insufficient space"); @@ -1018,20 +1082,17 @@ namespace build2 static bool empty (const vector<T>& x) {return x.empty ();} static const vector<T> empty_instance; - - // Make sure these are static-initialized together. Failed that VC will - // make sure it's done in the wrong order. - // - struct value_type_ex: build2::value_type - { - string type_name; - value_type_ex (value_type&&); - }; - static const value_type_ex value_type; + static const vector_value_type<T> value_type; }; // vector<pair<K, V>> // + // Either K or V can be optional<T> making the corresponding half of the + // pair optional. + // + template <typename K, typename V> + struct pair_vector_value_type; + template <typename K, typename V> struct value_traits<vector<pair<K, V>>> { @@ -1045,20 +1106,16 @@ namespace build2 static bool empty (const vector<pair<K, V>>& x) {return x.empty ();} static const vector<pair<K, V>> empty_instance; - - // Make sure these are static-initialized together. Failed that VC will - // make sure it's done in the wrong order. - // - struct value_type_ex: build2::value_type - { - string type_name; - value_type_ex (value_type&&); - }; - static const value_type_ex value_type; + static const pair_vector_value_type<K, V> value_type; }; // map<K, V> // + // Either K or V can be optional<T> making the key or value optional. + // + template <typename K, typename V> + struct map_value_type; + template <typename K, typename V> struct value_traits<std::map<K, V>> { @@ -1073,16 +1130,7 @@ namespace build2 static bool empty (const map<K, V>& x) {return x.empty ();} static const map<K, V> empty_instance; - - // Make sure these are static-initialized together. Failed that VC will - // make sure it's done in the wrong order. - // - struct value_type_ex: build2::value_type - { - string type_name; - value_type_ex (value_type&&); - }; - static const value_type_ex value_type; + static const map_value_type<K, V> value_type; }; // Explicitly pre-instantiate and export value_traits templates for @@ -1102,10 +1150,22 @@ namespace build2 value_traits<vector<pair<string, string>>>; extern template struct LIBBUILD2_DECEXPORT + value_traits<vector<pair<string, optional<string>>>>; + + extern template struct LIBBUILD2_DECEXPORT + value_traits<vector<pair<optional<string>, string>>>; + + extern template struct LIBBUILD2_DECEXPORT value_traits<std::map<string, string>>; extern template struct LIBBUILD2_DECEXPORT - value_traits<std::map<project_name, dir_path>>; + value_traits<std::map<string, optional<string>>>; + + extern template struct LIBBUILD2_DECEXPORT + value_traits<std::map<optional<string>, string>>; + + extern template struct LIBBUILD2_DECEXPORT + value_traits<std::map<project_name, dir_path>>; // var_subprojects // Project-wide (as opposed to global) variable overrides (see context ctor // for details). |