Open Radar

 
25-Jun-2012 10:24 AM Heath Borders:
Summary:
Xcode's dispatch_after template

double delayInSeconds = 2.0;
double delayInNanoSeconds = delayInSeconds * NSEC_PER_SEC;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInNanoSeconds);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
});

causes the following warning from CLANG_WARN_SUSPICIOUS_IMPLICIT_CONVERSION

Implicit conversion turns floating-point number into integer: 'double' to 'int64_t' (aka 'long long')

because

delayInNanoSeconds is converted from a double to an int64_t implicitly

Steps to Reproduce:
type "dispatch_after" into a function context in Xcode

Expected Results:
A code template that is free of warnings

Actual Results:
Implicit conversion turns floating-point number into integer: 'double' to 'int64_t' (aka 'long long')

Regression:

Notes:
Explicit casting stops the warning:

dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)delayInNanoSeconds);