1 use std::env; 2 main()3fn main() { 4 let ac = autocfg::new(); 5 6 ac.emit_expression_cfg( 7 "unsafe { 1f64.to_int_unchecked::<i32>() }", 8 "has_to_int_unchecked", 9 ); 10 11 ac.emit_expression_cfg("1u32.reverse_bits()", "has_reverse_bits"); 12 ac.emit_expression_cfg("1u32.trailing_ones()", "has_leading_trailing_ones"); 13 ac.emit_expression_cfg("1u32.div_euclid(1u32)", "has_div_euclid"); 14 15 if env::var_os("CARGO_FEATURE_STD").is_some() { 16 ac.emit_expression_cfg("1f64.copysign(-1f64)", "has_copysign"); 17 } 18 ac.emit_expression_cfg("1f64.is_subnormal()", "has_is_subnormal"); 19 20 ac.emit_expression_cfg("1u32.to_ne_bytes()", "has_int_to_from_bytes"); 21 ac.emit_expression_cfg("3.14f64.to_ne_bytes()", "has_float_to_from_bytes"); 22 23 autocfg::rerun_path("build.rs"); 24 } 25