有重载的情况下，传参有时需要显式类型：

float float f = 1.0F
double double d = 1D;
decimal decimal d = 1,0M
uint unit i = 1U;
long long i = 1L;
ulong ulong i = 1UL;

参考：https://www.jianshu.com/p/eb45efd9d3ce