From 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 7 Apr 2024 13:41:34 -0500 Subject: new repository --- devdocs/c/types%2Flimits.html | 218 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 218 insertions(+) create mode 100644 devdocs/c/types%2Flimits.html (limited to 'devdocs/c/types%2Flimits.html') diff --git a/devdocs/c/types%2Flimits.html b/devdocs/c/types%2Flimits.html new file mode 100644 index 00000000..ea79ff4c --- /dev/null +++ b/devdocs/c/types%2Flimits.html @@ -0,0 +1,218 @@ +

Numeric limits

Limits of integer types

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Limits of core language integer types
Defined in header <limits.h>
BOOL_WIDTH
+
(C23)
 bit width of _Bool
(macro constant)
CHAR_BIT
 number of bits in a byte
(macro constant)
MB_LEN_MAX
 maximum number of bytes in a multibyte character
(macro constant)
CHAR_WIDTH
+
(C23)
 bit width of char, same as CHAR_BIT
(macro constant)
CHAR_MIN
 minimum value of char
(macro constant)
CHAR_MAX
 maximum value of char
(macro constant)
SCHAR_WIDTHSHRT_WIDTHINT_WIDTHLONG_WIDTHLLONG_WIDTH
+
(C23)(C23)(C23)(C23)(C23)
 bit width of signed char, short, int, long, and long long respectively
(macro constant)
SCHAR_MINSHRT_MININT_MINLONG_MINLLONG_MIN
+
(C99)
 minimum value of signed char, short, int, long and long long respectively
(macro constant)
SCHAR_MAXSHRT_MAXINT_MAXLONG_MAXLLONG_MAX
+
(C99)
 maximum value of signed char, short, int, long and long long respectively
(macro constant)
UCHAR_WIDTHUSHRT_WIDTHUINT_WIDTHULONG_WIDTHULLONG_WIDTH
+
(C23)(C23)(C23)(C23)(C23)
 bit width of unsigned char, unsigned short, unsigned int, unsigned long, and unsigned long long respectively
(macro constant)
UCHAR_MAXUSHRT_MAXUINT_MAXULONG_MAXULLONG_MAX
+
(C99)
 maximum value of unsigned char, unsigned short, unsigned int,
unsigned long and unsigned long long respectively
(macro constant)
BITINT_MAXWIDTH
+
(C23)
 maximum width N supported by the declaration of a bit-precise integer in the type specifier _BitInt(N), greater than or equal to ULLONG_WIDTH
(macro constant)
Limits of library type aliases
Defined in header <stdint.h>
PTRDIFF_WIDTH
+
(C23)
 bit width of object of ptrdiff_t type
(macro constant)
PTRDIFF_MIN
+
(C99)
 minimum value of ptrdiff_t
(macro constant)
PTRDIFF_MAX
+
(C99)
 maximum value of ptrdiff_t
(macro constant)
SIZE_WIDTH
+
(C23)
 bit width of object of size_t type
(macro constant)
SIZE_MAX
+
(C99)
 maximum value of size_t
(macro constant)
SIG_ATOMIC_WIDTH
+
(C23)
 bit width of object of sig_atomic_t type
(macro constant)
SIG_ATOMIC_MIN
+
(C99)
 minimum value of sig_atomic_t
(macro constant)
SIG_ATOMIC_MAX
+
(C99)
 maximum value of sig_atomic_t
(macro constant)
WINT_WIDTH
+
(C23)
 bit width of object of wint_t type
(macro constant)
WINT_MIN
+
(C99)
 minimum value of wint_t
(macro constant)
WINT_MAX
+
(C99)
 maximum value of wint_t
(macro constant)
Defined in header <wchar.h>
Defined in header <stdint.h>
WCHAR_WIDTH
+
(C23)
 bit width of object of wchar_t type
(macro constant)
WCHAR_MIN
+
(C99)
 minimum value of wchar_t
(macro constant)
WCHAR_MAX
+
(C99)
 maximum value of wchar_t
(macro constant)

Notes

The types of these constants, other than CHAR_BIT and MB_LEN_MAX, are required to match the results of the integral promotions as applied to objects of the types they describe: CHAR_MAX may have type int or unsigned int, but never char. Similarly USHRT_MAX may not be of an unsigned type: its type may be int.

+

A freestanding implementation may lack sig_atomic_t and/or wint_t typedef names, in which case the SIG_ATOMIC_* and/or WINT_* macros are correspondingly absent.

+

Example

#include <limits.h>
+#include <stdint.h>
+#include <stdio.h>
+ 
+int main(void)
+{
+    printf("CHAR_BIT       = %d\n", CHAR_BIT);
+    printf("MB_LEN_MAX     = %d\n\n", MB_LEN_MAX);
+ 
+    printf("CHAR_MIN       = %+d\n", CHAR_MIN);
+    printf("CHAR_MAX       = %+d\n", CHAR_MAX);
+    printf("SCHAR_MIN      = %+d\n", SCHAR_MIN);
+    printf("SCHAR_MAX      = %+d\n", SCHAR_MAX);
+    printf("UCHAR_MAX      = %u\n\n", UCHAR_MAX);
+ 
+    printf("SHRT_MIN       = %+d\n", SHRT_MIN);
+    printf("SHRT_MAX       = %+d\n", SHRT_MAX);
+    printf("USHRT_MAX      = %u\n\n", USHRT_MAX);
+ 
+    printf("INT_MIN        = %+d\n", INT_MIN);
+    printf("INT_MAX        = %+d\n", INT_MAX);
+    printf("UINT_MAX       = %u\n\n", UINT_MAX);
+ 
+    printf("LONG_MIN       = %+ld\n", LONG_MIN);
+    printf("LONG_MAX       = %+ld\n", LONG_MAX);
+    printf("ULONG_MAX      = %lu\n\n", ULONG_MAX);
+ 
+    printf("LLONG_MIN      = %+lld\n", LLONG_MIN);
+    printf("LLONG_MAX      = %+lld\n", LLONG_MAX);
+    printf("ULLONG_MAX     = %llu\n\n", ULLONG_MAX);
+ 
+    printf("PTRDIFF_MIN    = %td\n", PTRDIFF_MIN);
+    printf("PTRDIFF_MAX    = %+td\n", PTRDIFF_MAX);
+    printf("SIZE_MAX       = %zu\n", SIZE_MAX);
+    printf("SIG_ATOMIC_MIN = %+jd\n",(intmax_t)SIG_ATOMIC_MIN);
+    printf("SIG_ATOMIC_MAX = %+jd\n",(intmax_t)SIG_ATOMIC_MAX);
+    printf("WCHAR_MIN      = %+jd\n",(intmax_t)WCHAR_MIN);
+    printf("WCHAR_MAX      = %+jd\n",(intmax_t)WCHAR_MAX);
+    printf("WINT_MIN       = %jd\n", (intmax_t)WINT_MIN);
+    printf("WINT_MAX       = %jd\n", (intmax_t)WINT_MAX);
+}

Possible output:

+
CHAR_BIT       = 8
+MB_LEN_MAX     = 16
+ 
+CHAR_MIN       = -128
+CHAR_MAX       = +127
+SCHAR_MIN      = -128
+SCHAR_MAX      = +127
+UCHAR_MAX      = 255
+ 
+SHRT_MIN       = -32768
+SHRT_MAX       = +32767
+USHRT_MAX      = 65535
+ 
+INT_MIN        = -2147483648
+INT_MAX        = +2147483647
+UINT_MAX       = 4294967295
+ 
+LONG_MIN       = -9223372036854775808
+LONG_MAX       = +9223372036854775807
+ULONG_MAX      = 18446744073709551615
+ 
+LLONG_MIN      = -9223372036854775808
+LLONG_MAX      = +9223372036854775807
+ULLONG_MAX     = 18446744073709551615
+ 
+PTRDIFF_MIN    = -9223372036854775808
+PTRDIFF_MAX    = +9223372036854775807
+SIZE_MAX       = 18446744073709551615
+SIG_ATOMIC_MIN = -2147483648
+SIG_ATOMIC_MAX = +2147483647
+WCHAR_MIN      = -2147483648
+WCHAR_MAX      = +2147483647
+WINT_MIN       = 0
+WINT_MAX       = 4294967295

Limits of floating-point types

+ + + + + + + + + + + + + + + +
Defined in header <float.h>
FLT_RADIX
 the radix (integer base) used by the representation of all three floating-point types
(macro constant)
DECIMAL_DIG
+
(C99)
 conversion from long double to decimal with at least DECIMAL_DIG digits and back to long double is the identity conversion: this is the decimal precision required to serialize/deserialize a long double
(macro constant)
FLT_DECIMAL_DIGDBL_DECIMAL_DIGLDBL_DECIMAL_DIG
+
(C11)
 conversion from float/double/long double to decimal with at least FLT_DECIMAL_DIG/DBL_DECIMAL_DIG/LDBL_DECIMAL_DIG digits and back is the identity conversion: this is the decimal precision required to serialize/deserialize a floating-point value. Defined to at least 6, 10, and 10 respectively, or 9 for IEEE float and 17 for IEEE double (see also the C++ analog: max_digits10)
(macro constant)
FLT_MINDBL_MINLDBL_MIN
 minimum, normalized, positive value of float, double and long double respectively
(macro constant)
FLT_TRUE_MINDBL_TRUE_MINLDBL_TRUE_MIN
+
(C11)
 minimum positive value of float, double and long double respectively
(macro constant)
FLT_MAXDBL_MAXLDBL_MAX
 maximum finite value of float, double and long double respectively
(macro constant)
FLT_EPSILONDBL_EPSILONLDBL_EPSILON
 absolute value difference between 1.0 and the next representable value for float, double and long double respectively
(macro constant)
FLT_DIGDBL_DIGLDBL_DIG
 number of decimal digits that are guaranteed to be preserved in text → float/double/long double → text roundtrip without change due to rounding or overflow (see the C++ analog digits10 for detail)
(macro constant)
FLT_MANT_DIGDBL_MANT_DIGLDBL_MANT_DIG
 number of base-FLT_RADIX digits that are in the floating-point mantissa and that can be represented without losing precision for float, double and long double respectively
(macro constant)
FLT_MIN_EXPDBL_MIN_EXPLDBL_MIN_EXP
 minimum negative integer such that FLT_RADIX raised by power one less than that integer is a normalized float, double and long double respectively
(macro constant)
FLT_MIN_10_EXPDBL_MIN_10_EXPLDBL_MIN_10_EXP
 minimum negative integer such that 10 raised by power one less than that integer is a normalized float, double and long double respectively
(macro constant)
FLT_MAX_EXPDBL_MAX_EXPLDBL_MAX_EXP
 maximum positive integer such that FLT_RADIX raised by power one less than that integer is a representable finite float, double and long double respectively
(macro constant)
FLT_MAX_10_EXPDBL_MAX_10_EXPLDBL_MAX_10_EXP
 maximum positive integer such that 10 raised by power one less than that integer is a representable finite float, double and long double respectively
(macro constant)
rounding mode of floating-point arithmetic
(macro constant)
+
(C99)
 use of extended precision for intermediate results:
​0​ – not used, 1 – double is used instead of float, 2 – long double is used
(macro constant)
+
FLT_HAS_SUBNORMDBL_HAS_SUBNORMLDBL_HAS_SUBNORM
+
(C11)(deprecated in C23)
 whether the type supports subnormal (denormal) numbers:
-1 – indeterminable, ​0​ – absent, 1 – present
(macro constant)

Example

#include <float.h>
+#include <math.h>
+#include <stdio.h>
+ 
+int main(void)
+{
+    printf("DECIMAL_DIG     = %d\n", DECIMAL_DIG);
+    printf("FLT_DECIMAL_DIG = %d\n", FLT_DECIMAL_DIG);
+    printf("FLT_RADIX       = %d\n", FLT_RADIX);
+    printf("FLT_MIN         = %e\n", FLT_MIN);
+    printf("FLT_MAX         = %e\n", FLT_MAX);
+    printf("FLT_EPSILON     = %e\n", FLT_EPSILON);
+    printf("FLT_DIG         = %d\n", FLT_DIG);
+    printf("FLT_MANT_DIG    = %d\n", FLT_MANT_DIG);
+    printf("FLT_MIN_EXP     = %d\n", FLT_MIN_EXP);
+    printf("FLT_MIN_10_EXP  = %d\n", FLT_MIN_10_EXP);
+    printf("FLT_MAX_EXP     = %d\n", FLT_MAX_EXP);
+    printf("FLT_MAX_10_EXP  = %d\n", FLT_MAX_10_EXP);
+    printf("FLT_ROUNDS      = %d\n", FLT_ROUNDS);
+    printf("FLT_EVAL_METHOD = %d\n", FLT_EVAL_METHOD);
+    printf("FLT_HAS_SUBNORM = %d\n", FLT_HAS_SUBNORM);
+}

Possible output:

+
DECIMAL_DIG     = 37
+FLT_DECIMAL_DIG = 9
+FLT_RADIX       = 2
+FLT_MIN         = 1.175494e-38
+FLT_MAX         = 3.402823e+38
+FLT_EPSILON     = 1.192093e-07
+FLT_DIG         = 6
+FLT_MANT_DIG    = 24
+FLT_MIN_EXP     = -125
+FLT_MIN_10_EXP  = -37
+FLT_MAX_EXP     = 128
+FLT_MAX_10_EXP  = 38
+FLT_ROUNDS      = 1
+FLT_EVAL_METHOD = 1
+FLT_HAS_SUBNORM = 1

References

See also

+
C++ documentation for C numeric limits interface
+

+ © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
+ https://en.cppreference.com/w/c/types/limits +

+
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