Hi! This is basically the result of a discussion on the STLport mailinglist. The question came up what this code means: #if defined(_BIG_ENDIAN) 0x7f80 << (sizeof(int)*CHAR_BIT-16), #else 0x7f800000, #endif This is from detail/limits.hpp. The puzzling thing is that the result for big-endian targets is exactly the same, unless the size of an int is not 32 bit, but the size of the int has nothing to do with endianess still... I dug around a bit, and it was added some time ago by John Maddock with the comment that it adds support for big-endian SPARC machines, but later also used for big-endian MIPS and PPC. There also used to be a comment saying something like: "making this depend on big-endian targets is wrong, it's the layout of floats we care about, not the layout of integers when written to memory". This comment was removed when the ad-hoc endian detection was replaced with the centralized one. Can anybody see what this code is supposed to do? I understand that 0x7f800000 is an integer with the same bit layout as one of the special floating point constants, but I can't figure out why it would be any different on big-endian machines. Uli