[f2f]

In Go, floating-point constants may have very high precision, so that arithmetic involving them is more accurate. The constants defined in the math package are given with many more digits than are available in a float64.

Having so many digits available means that calculations like Pi/2 or other more intricate evaluations can carry more precision until the result is assigned, making calculations involving constants easier to write without losing precision. It also means that there is no occasion in which the floating-point corner cases like infinities, soft underflows, and NaNs arise in constant expressions.