diff options
Diffstat (limited to 'libbuild2/variable.hxx')
| -rw-r--r-- | libbuild2/variable.hxx | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/libbuild2/variable.hxx b/libbuild2/variable.hxx index 400aaf1..2942f1c 100644 --- a/libbuild2/variable.hxx +++ b/libbuild2/variable.hxx @@ -48,7 +48,11 @@ namespace build2 template <typename T> const value_type* is_a () const; - // Element type, if this is a vector. + // True if the type is a container. + // + bool container; + + // Element type, if this is a container and the element type is named. // const value_type* element_type; @@ -75,9 +79,11 @@ namespace build2 void (*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. + // implementation if necessary. If reduce is true, then for an empty + // simple value return an empty list rather than a list of one empty name. + // Note that the value cannot be NULL. // - names_view (*const reverse) (const value&, names& storage); + names_view (*const reverse) (const value&, names& storage, bool reduce); // Cast value::data_ storage to value type so that the result can be // static_cast to const T*. If it is NULL, then cast data_ directly. Note @@ -363,8 +369,8 @@ namespace build2 // public: // Assign/append/prepend a typed value. For assign, LHS should be either - // of the same type or untyped. For append, LHS should be either of the - // same type or untyped and NULL. + // of the same type or untyped. For append/prepend, LHS should be either + // of the same type or untyped and NULL. // template <typename T> value& operator= (T); template <typename T> value& operator+= (T); @@ -497,18 +503,20 @@ namespace build2 typify_atomic (context&, value&, const value_type&, const variable*); // Remove value type from the value reversing it to names. This is similar - // to reverse() below except that it modifies the value itself. + // to reverse() below except that it modifies the value itself. Note that + // the reduce semantics applies to empty but not null. // - LIBBUILD2_SYMEXPORT void untypify (value&); + LIBBUILD2_SYMEXPORT void untypify (value&, bool reduce); // Reverse the value back to names. The value should not be NULL and storage - // should be empty. + // should be empty. If reduce is true, then for an empty simple value return + // an empty list rather than a list of one empty name. // vector_view<const name> - reverse (const value&, names& storage); + reverse (const value&, names& storage, bool reduce); vector_view<name> - reverse (value&, names& storage); + reverse (value&, names& storage, bool reduce); // Variable lookup result, AKA, binding of a variable to a value. // |