This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
Section 7.3.11 [conv.fpint] paragraph 1 states:
An rvalue of a floating point type can be converted to an rvalue of an integer type. The conversion truncates; that is, the fractional part is discarded.
Here, the concepts of “truncation” and “fractional part” seem to be used without precise definitions. When -3.14 is converted into an integer, is the truncation toward zero or away from zero? Is the fractional part -0.14 or 0.86? The standard seem to give no clear answer to these.
Replace “truncates” with “truncates toward zero.”
Replace “the fractional part” with “the fractional part (where that of x is defined as x-floor(x) for nonnegative x and x-ceiling(x) for negative x);” there should be a better wording for this, or the entire statement “that is, the fractional part is discarded” can be removed, once the meaning of “truncation” becomes unambiguous as above.
Rationale (October, 2006):
The specification is clear enough: “fractional part” refers to the digits following the decimal point, so that -3.14 converted to int becomes -3.