[ 2010-10-29 Daniel comments: ]

I believe both paragraphs need more cleanup: First, the current Requires element conflict with the Remark; second, it seems to me that the whole single Requires element is intended to be split into a Requires and an Effects element; third, the reference to tuple is incorrect (noticed by Paolo Carlini); fourth, it refers to some non-existing InputIterator parameter relevant for a completely different overload; sixth, the return type of the overload with hint is wrong. The following proposed resolution tries to solve these issues as well and uses similar wording as for the corresponding unordered containers. Unfortunately it has some redundancy over Table 99, but I did not remove the specification because of the more general template parameter P - the Table 99 requirements apply only for an argument identical to value_type.

Daniel's Proposed resolution (not current):

1. Change [map.modifiers] around p. 1 as indicated:

   template <class P> pair<iterator, bool> insert(P&& x);
   template <class P> pair<iterator, bool> insert(const_iterator position, P&& x);
   

   1 Requires: P shall be convertible to value_type is constructible from std::forward<P>(x)..

   If P is instantiated as a reference type, then the argument x is copied from. Otherwise x is considered to be an rvalue as it is converted to value_type and inserted into the map. Specifically, in such cases CopyConstructible is not required of key_type or mapped_type unless the conversion from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, then key_type must be CopyConstructible). The signature taking InputIterator parameters does not require CopyConstructible of either key_type or mapped_type if the dereferenced InputIterator returns a non-const rvalue pair<key_type,mapped_type>. Otherwise CopyConstructible is required for both key_type and mapped_type.
   ? Effects: Inserts x converted to value_type if and only if there is no element in the container with key equivalent to the key of value_type(x). For the second form, the iterator position is a hint pointing to where the search should start.

   ? Returns: For the first form, the bool component of the returned pair object indicates whether the insertion took place and the iterator component - or for the second form the returned iterator - points to the element with key equivalent to the key of value_type(x).

   ? Complexity: Logarithmic in general, but amortized constant if x is inserted right before position.

   ? Remarks: These signatures shall not participate in overload resolution unless P is implicitly convertible to value_type.

2. Change [multimap.modifiers] around p. 1 as indicated:

   template <class P> iterator insert(P&& x);
   template <class P> iterator insert(const_iterator position, P&& x);
   

   1 Requires: P shall be convertible to value_type is constructible from std::forward<P>(x).

   If P is instantiated as a reference type, then the argument x is copied from. Otherwise x is considered to be an rvalue as it is converted to value_type and inserted into the map. Specifically, in such cases CopyConstructible is not required of key_type or mapped_type unless the conversion from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, then key_type must be CopyConstructible). The signature taking InputIterator parameters does not require CopyConstructible of either key_type or mapped_type if the dereferenced InputIterator returns a non-const rvalue pair<key_type, mapped_type>. Otherwise CopyConstructible is required for both key_type and mapped_type.
   ? Effects: Inserts x converted to value_type. For the second form, the iterator position is a hint pointing to where the search should start.

   ? Returns: An iterator that points to the element with key equivalent to the key of value_type(x).

   ? Complexity: Logarithmic in general, but amortized constant if x is inserted right before position.

   ? Remarks: These signatures shall not participate in overload resolution unless P is implicitly convertible to value_type.