Assume has_copysign

Author: cuviper

build.rs

@@ -1,11 +1,6 @@
-use std::env;
-
 fn main() {
     let ac = autocfg::new();
 
-    if env::var_os("CARGO_FEATURE_STD").is_some() {
-        ac.emit_expression_cfg("1f64.copysign(-1f64)", "has_copysign");
-    }
     ac.emit_expression_cfg("1f64.is_subnormal()", "has_is_subnormal");
     ac.emit_expression_cfg("1f64.total_cmp(&2f64)", "has_total_cmp");
 

src/float.rs

@@ -1944,10 +1944,6 @@ macro_rules! float_impl_std {
                 Self::asinh(self) -> Self;
                 Self::acosh(self) -> Self;
                 Self::atanh(self) -> Self;
-            }
-
-            #[cfg(has_copysign)]
-            forward! {
                 Self::copysign(self, sign: Self) -> Self;
             }