std.math

The C math library's functions on f64. Their last bit depends on which libm the program links (glibc, musl and CUDA's differ), unlike the builtins sqrt, floor, ceil, trunc and abs, which IEEE 754 makes the same everywhere. That dependency shows in every caller's row as ffi:. Host only. Cost: one library call each, no allocation, no errno read.

pub const PI:f64 = 3.141592653589793;
pub const E:f64 = 2.718281828459045;
pub fn exp(x:f64) -> f64  // effects: ffi:exp
pub fn log(x:f64) -> f64  // effects: ffi:log
pub fn log2(x:f64) -> f64  // effects: ffi:log2
pub fn pow(x:f64, y:f64) -> f64  // effects: ffi:pow
pub fn sin(x:f64) -> f64  // effects: ffi:sin
pub fn cos(x:f64) -> f64  // effects: ffi:cos
pub fn tan(x:f64) -> f64  // effects: ffi:tan
pub fn atan2(y:f64, x:f64) -> f64  // effects: ffi:atan2

A generic function's effects are what it may do for any arguments within its bounds, besides what their own trait members do.