#2 Boost.Filesystem generic_string not found

[grvs]

A user reports the following error when attempting to build Boost:

g++ -DHAVE_CONFIG_H -I. -I../.. -Wall -Wextra -ggdb3 -O0 -Wold-style-cast -fno-pretty-templates -MT libexttools_a-ToolCompiler.o -MD -MP -MF .deps/libexttools_a-ToolCompiler.Tpo -c -o libexttools_a-ToolCompiler.o `test -f 'ToolCompiler.cpp' || echo './'`ToolCompiler.cpp
ToolCompiler.cpp: In member function ‘int ToolCompiler::GenerateCFG(const std::string&, const std::string&)’:
ToolCompiler.cpp:86:58: error: ‘struct boost::filesystem::path’ has no member named ‘generic_string’
ToolCompiler.cpp:104:78: error: ‘struct boost::filesystem::path’ has no member named ‘generic_string’

This is with configure detecting Boost >= 1.42.0.