1lround(3M) Mathematical Library Functions lround(3M)
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6 lround, lroundf, lroundl - round to nearest integer value
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9 c99 [ flag... ] file... -lm [ library... ]
10 #include <math.h>
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12 long lround(double x);
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15 long lroundf(float x);
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18 long lroundl(long double x);
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22 These functions round their argument to the nearest integer value,
23 rounding halfway cases away from zero, regardless of the current round‐
24 ing direction.
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27 Upon successful completion, these functions return the rounded integer
28 value.
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31 If x is NaN, a domain error occurs and an unspecified value is
32 returned.
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35 If x is +Inf, a domain error occurs and an unspecified value is
36 returned.
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39 If x is −Inf, a domain error occurs and an unspecified value is
40 returned.
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43 If the correct value is positive and too large to represent as a long,
44 a domain error occurs and an unspecified value is returned.
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47 If the correct value is negative and too large to represent as a long,
48 a domain error occurs and an unspecified value is returned.
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51 These functions will fail if:
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53 Domain Error The x argument is NaN or ±Inf, or the correct value is
54 not representable as an integer.
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56 If the integer expression (math_errhandling &
57 MATH_ERREXCEPT) is non-zero, then the invalid floating-
58 point exception is raised.
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62 An application wanting to check for exceptions should call feclearex‐
63 cept(FE_ALL_EXCEPT) before calling these functions. On return, if
64 fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is
65 non-zero, an exception has been raised. An application should either
66 examine the return value or check the floating point exception flags to
67 detect exceptions.
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70 See attributes(5) for descriptions of the following attributes:
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75 ┌─────────────────────────────┬─────────────────────────────┐
76 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
77 ├─────────────────────────────┼─────────────────────────────┤
78 │Interface Stability │Standard │
79 ├─────────────────────────────┼─────────────────────────────┤
80 │MT-Level │MT-Safe │
81 └─────────────────────────────┴─────────────────────────────┘
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84 feclearexcept(3M), fetestexcept(3M), llround(3M), math.h(3HEAD),
85 attributes(5), standards(5)
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89SunOS 5.11 12 Jul 2006 lround(3M)