Hi, I currently use the latest trunk version of boost. I have the following precompiled header: precompile.h: #include <boost/timer.hpp> When I compile using Visual Studio 2005 on Windows Vista x86, I get the following errors (Note that this is a very long list). I'm not sure why this is happening. If anyone could offer some advice I'd greatly appreciate it. Thank you. 1>c:\program files\microsoft visual studio 8\vc\include\cmath(18) : error C2039: 'acosf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(18) : error C2873: 'acosf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(18) : error C2039: 'asinf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(18) : error C2873: 'asinf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(19) : error C2039: 'atanf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(19) : error C2873: 'atanf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(19) : error C2039: 'atan2f' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(19) : error C2873: 'atan2f' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(19) : error C2039: 'ceilf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(19) : error C2873: 'ceilf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(20) : error C2039: 'cosf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(20) : error C2873: 'cosf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(20) : error C2039: 'coshf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(20) : error C2873: 'coshf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(20) : error C2039: 'expf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(20) : error C2873: 'expf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(21) : error C2039: 'fabsf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(21) : error C2873: 'fabsf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(21) : error C2039: 'floorf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(21) : error C2873: 'floorf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(21) : error C2039: 'fmodf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(21) : error C2873: 'fmodf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(22) : error C2039: 'frexpf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(22) : error C2873: 'frexpf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(22) : error C2039: 'ldexpf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(22) : error C2873: 'ldexpf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(22) : error C2039: 'logf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(22) : error C2873: 'logf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(23) : error C2039: 'log10f' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(23) : error C2873: 'log10f' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(23) : error C2039: 'modff' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(23) : error C2873: 'modff' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(23) : error C2039: 'powf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(23) : error C2873: 'powf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(24) : error C2039: 'sinf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(24) : error C2873: 'sinf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(24) : error C2039: 'sinhf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(24) : error C2873: 'sinhf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(24) : error C2039: 'sqrtf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(24) : error C2873: 'sqrtf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(25) : error C2039: 'tanf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(25) : error C2873: 'tanf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(25) : error C2039: 'tanhf' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(25) : error C2873: 'tanhf' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(27) : error C2039: 'acosl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(27) : error C2873: 'acosl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(27) : error C2039: 'asinl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(27) : error C2873: 'asinl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(28) : error C2039: 'atanl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(28) : error C2873: 'atanl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(28) : error C2039: 'atan2l' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(28) : error C2873: 'atan2l' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(28) : error C2039: 'ceill' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(28) : error C2873: 'ceill' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(29) : error C2039: 'cosl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(29) : error C2873: 'cosl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(29) : error C2039: 'coshl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(29) : error C2873: 'coshl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(29) : error C2039: 'expl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(29) : error C2873: 'expl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(30) : error C2039: 'fabsl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(30) : error C2873: 'fabsl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(30) : error C2039: 'floorl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(30) : error C2873: 'floorl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(30) : error C2039: 'fmodl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(30) : error C2873: 'fmodl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(31) : error C2039: 'frexpl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(31) : error C2873: 'frexpl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(31) : error C2039: 'ldexpl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(31) : error C2873: 'ldexpl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(31) : error C2039: 'logl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(31) : error C2873: 'logl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(32) : error C2039: 'log10l' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(32) : error C2873: 'log10l' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(32) : error C2039: 'modfl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(32) : error C2873: 'modfl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(32) : error C2039: 'powl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(32) : error C2873: 'powl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(33) : error C2039: 'sinl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(33) : error C2873: 'sinl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(33) : error C2039: 'sinhl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(33) : error C2873: 'sinhl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(33) : error C2039: 'sqrtl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(33) : error C2873: 'sqrtl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(34) : error C2039: 'tanl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(34) : error C2873: 'tanl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(34) : error C2039: 'tanhl' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(34) : error C2873: 'tanhl' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(36) : error C2039: 'abs' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(36) : error C2873: 'abs' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(37) : error C2039: 'acos' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(37) : error C2873: 'acos' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(37) : error C2039: 'asin' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(37) : error C2873: 'asin' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(38) : error C2039: 'atan' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(38) : error C2873: 'atan' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(38) : error C2039: 'atan2' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(38) : error C2873: 'atan2' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(38) : error C2039: 'ceil' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(38) : error C2873: 'ceil' : symbol cannot be used in a using-declaration 1>c:\program files\microsoft visual studio 8\vc\include\cmath(39) : error C2039: 'cos' : is not a member of '`global namespace'' 1>c:\program files\microsoft visual studio 8\vc\include\cmath(39) : fatal error C1003: error count exceeds 100; stopping compilation