[#BloombergLP-bslstl-MapComparator-0d-operator_call-0829] = xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bslstl.adoc[bslstl]::xref:BloombergLP/bslstl/MapComparator-0d.adoc[MapComparator]::operator() :relfileprefix: ../../../ :mrdocs: Return `true` if the specified `lhs` is less than (ordered before, according to the comparator held by this object) `value().first` of the specified `rhs` after being cast to `NodeType`, and `false` otherwise. The behavior is undefined unless `rhs` can be safely cast to `NodeType`. == Synopsis Declared in `<bslstl_mapcomparator.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- template<class LOOKUP_KEY> bool operator()( LOOKUP_KEY const& lhs, xref:BloombergLP/bslalg/RbTreeNode.adoc[bslalg::RbTreeNode] const& rhs) const; ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#