ここで問題を見た人はいますか?
double latDouble = [latString doubleValue];
double lngDouble = [lngString doubleValue];
CGFloat dist = [self calcDiffDistance:latDouble withPostLng:lngDouble]; // Incompatible types in initialization
- (float)calcDiffDistance:(double)postLat withPostLng:(double)lon1
{
...
}