I am trying something looking fairly reasonable: string str1 = boost::replace_all_copy(str, 'x', '0'); It obviously fails to compile with: error: no matching function for call to 'begin(const char&)' error: no matching function for call to 'end(const char&)' as replace_all_copy() wants boost::ranges for the 2nd and 3rd parameters: replace_all_copy( const SequenceT &, const Range1T &, const Range2T &); and 'x' and '0' are not boost::ranges. Would that be sensible to extend boost::range along the following lines to allow string_algo to work with individual characters? namespace boost { template<> struct range_iterator<char> { typedef char* type; }; template<> struct range_const_iterator<char> { typedef char const* type; }; namespace range_detail { template<> inline char const* boost_range_begin(char const& c) { return &c; } template<> inline char const* boost_range_end(char const& c) { return &c + 1; } } } Thanks, Vladimir. P.S. I do understand that the following works string str1 = boost::replace_all_copy(str, "x", "0");