Fix Wimplicit-int-conversion-on-negation #355
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bjosv
reviewed
Aug 18, 2025
| if ((sign = n < 0)) { | ||
| *p++ = '-'; | ||
| n = -n; | ||
| n = (int8_t)-n; |
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An alternative seems to be n *= -1; which also silences the warning..but I don't know if that is a glitch in clang.
Feels like that also would be an implicit conversion due to integer promotion.
bjosv
approved these changes
Aug 18, 2025
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Clang 21 adds the warning Wimplicit-int-conversion-on-negation which is when a smaller integer type (char, short) is negated and then converted back to to the smaller type, since negation implicitly converts the value to int.
Adding the casts here should stop the warning.