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# float, double, long double

 P: n/a Does the Standard specify any minimum range or minimum precision for the float, double and long double. I haven't found anything in the Standard about it. -JKop Jul 22 '05 #1
4 Replies

 P: n/a > Does the Standard specify any minimum range or minimum precision for the float, double and long double. I haven't found anything in the Standard about it. Yes: Float must offer at least the equivalent of 6 decimal digits of precision; double and long double must offer at least the equivalent of 10 digits. In practice, virtually all implementations use the machine's native floating-point types; on most machines today those offer approximately 6 digits for float and 16 digits for double. Implementations are less consistent for long double, but double is good enough for most applications anyway. Jul 22 '05 #2

 P: n/a "Andrew Koenig" In practice, virtually all implementations use the machine's native floating-point types; on most machines today those offer approximately 6 digits for float and 16 digits for double. Borland C++ documents have always stated 7 for float and 15 for double. Fraser. Jul 22 '05 #3

 P: n/a On Sat, 07 Aug 2004 20:14:05 GMT, JKop wrote in comp.lang.c++: Does the Standard specify any minimum range or minimum precision for the float, double and long double. I haven't found anything in the Standard about it. -JKop This is one of those cases where the C++ standard adopts the requirements of the C standard without repeating the text. Section 5.2.4.2 Numerical limits spells out the minimum ranges for all integer and floating point types, and minimum precision and several other important factors for the floating point types. An implementation, C or C++, is required to document its implementation. The section number is the same in both the older version of the C standard which the C++ standard includes, and the current C standard. -- Jack Klein Home: http://JK-Technology.Com FAQs for comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html comp.lang.c++ http://www.parashift.com/c++-faq-lite/ alt.comp.lang.learn.c-c++ http://www.contrib.andrew.cmu.edu/~a...FAQ-acllc.html Jul 22 '05 #4

 P: n/a Jack Klein posted: This is one of those cases where the C++ standard adopts the requirements of the C standard without repeating the text. Section 5.2.4.2 Numerical limits spells out the minimum ranges for all integer and floating point types, and minimum precision and several other important factors for the floating point types. An implementation, C or C++, is required to document its implementation. The section number is the same in both the older version of the C standard which the C++ standard includes, and the current C standard. Great! Now all I need is the C Standard. What ever happened to self- sufficency, self-containment? -JKop Jul 22 '05 #5

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