diff options
Diffstat (limited to 'build2/variable')
| -rw-r--r-- | build2/variable | 52 |
1 files changed, 29 insertions, 23 deletions
diff --git a/build2/variable b/build2/variable index ea60832..a5f2ea5 100644 --- a/build2/variable +++ b/build2/variable @@ -50,13 +50,13 @@ namespace build2 void (*const copy_assign) (value&, const value&, bool move); // While assign cannot be NULL, if append or prepend is NULL, then this - // means this type doesn't support this operation. Variable is provided - // primarily for diagnostics. Return true if the resulting value is not - // empty. + // means this type doesn't support this operation. Variable is optional + // and is provided only for diagnostics. Return true if the resulting + // value is not empty. // - bool (*const assign) (value&, names&&, const variable&); - bool (*const append) (value&, names&&, const variable&); - bool (*const prepend) (value&, names&&, const variable&); + bool (*const assign) (value&, names&&, const variable*); + bool (*const append) (value&, names&&, const variable*); + bool (*const prepend) (value&, names&&, const variable*); // Reverse the value back to a vector of names. Storage can be used by the // implementation if necessary. Cannot be NULL. @@ -141,10 +141,10 @@ namespace build2 bool operator== (nullptr_t) const {return null ();} bool operator!= (nullptr_t) const {return !null ();} - // Creation. A newly created value is NULL and can be reset back to NULL - // by assigning nullptr. Values can be copied and copy-assigned. Note that - // for assignment, the values' types should be the same or LHS should be - // untyped. + // Creation. A default-initialzied value is NULL and can be reset back to + // NULL by assigning nullptr. Values can be copied and copy-assigned. Note + // that for assignment, the values' types should be the same or LHS should + // be untyped. // // public: @@ -154,6 +154,9 @@ namespace build2 value (const value_type* t = nullptr) : type (t), state (value_state::null), extra (0) {} + explicit + value (names&&); // Create untyped value. + // Note: preserves type. // value& @@ -182,17 +185,17 @@ namespace build2 value& operator= (const char* v) {return *this = string (v);} value& operator+= (const char* v) {return *this += string (v);} - // Assign/append/prepend raw data. Variable is normally only used for - // diagnostics. + // Assign/append/prepend raw data. Variable is optional and is only used + // for diagnostics. // void - assign (names&&, const variable&); + assign (names&&, const variable*); void - append (names&&, const variable&); + append (names&&, const variable*); void - prepend (names&&, const variable&); + prepend (names&&, const variable*); // Implementation details, don't use directly except in representation // type implementations. @@ -224,8 +227,8 @@ namespace build2 reset (); }; - // The values should be of the same type (or both be untyped). NULL values - // compare equal. + // The values should be of the same type (or both be untyped) except NULL + // values can also be untyped. NULL values compare equal. // bool operator== (const value&, const value&); bool operator!= (const value&, const value&); @@ -249,12 +252,12 @@ namespace build2 template <typename T> const T* cast_null (const value&); template <typename T> const T* cast_null (const lookup&); - // Assign value type to the value. Variable is normally only used for - // diagnostics. + // Assign value type to the value. In the second version the variable is + // optional and is only used for diagnostics. // template <typename T> void typify (value&, const variable&); - void typify (value&, const value_type&, const variable&); + void typify (value&, const value_type&, const variable*); // Reverse the value back to names. The value should no be NULL and storage // should be empty. @@ -262,6 +265,9 @@ namespace build2 names_view reverse (const value&, names& storage); + vector_view<name> + reverse (value&, names& storage); + // lookup // // A variable can be undefined, NULL, or contain a (potentially empty) @@ -395,15 +401,15 @@ namespace build2 // template <typename T, bool empty> static bool - simple_assign (value&, names&&, const variable&); + simple_assign (value&, names&&, const variable*); template <typename T, bool empty> static bool - simple_append (value&, names&&, const variable&); + simple_append (value&, names&&, const variable*); template <typename T, bool empty> static bool - simple_prepend (value&, names&&, const variable&); + simple_prepend (value&, names&&, const variable*); // Default implementations of the reverse callback for simple types that // calls value_traits<T>::reverse() and adds the result to the vector. As a |