Use ff crate for Field traits

benches/bls12_381/fq.rs

@@ -1,7 +1,7 @@
 use rand::{Rand, SeedableRng, XorShiftRng};
 
+use ff::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 use pairing::bls12_381::*;
-use pairing::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 
 #[bench]
 fn bench_fq_repr_add_nocarry(b: &mut ::test::Bencher) {

benches/bls12_381/fq12.rs

@@ -1,7 +1,7 @@
 use rand::{Rand, SeedableRng, XorShiftRng};
 
+use ff::Field;
 use pairing::bls12_381::*;
-use pairing::Field;
 
 #[bench]
 fn bench_fq12_add_assign(b: &mut ::test::Bencher) {

benches/bls12_381/fq2.rs

@@ -1,7 +1,7 @@
 use rand::{Rand, SeedableRng, XorShiftRng};
 
+use ff::{Field, SqrtField};
 use pairing::bls12_381::*;
-use pairing::{Field, SqrtField};
 
 #[bench]
 fn bench_fq2_add_assign(b: &mut ::test::Bencher) {

benches/bls12_381/fr.rs

@@ -1,7 +1,7 @@
 use rand::{Rand, SeedableRng, XorShiftRng};
 
+use ff::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 use pairing::bls12_381::*;
-use pairing::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 
 #[bench]
 fn bench_fr_repr_add_nocarry(b: &mut ::test::Bencher) {

benches/pairing_benches.rs

@@ -1,5 +1,6 @@
 #![feature(test)]
 
+extern crate ff;
 extern crate pairing;
 extern crate rand;
 extern crate test;