1 use crate::consts::{constant, Constant};
2 use crate::utils::{match_trait_method, paths, snippet_with_applicability, span_lint_and_sugg};
3 use if_chain::if_chain;
4 use rustc_errors::Applicability;
6 use rustc_lint::LateContext;
8 use super::ITER_NTH_ZERO;
10 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, nth_args: &'tcx [hir::Expr<'_>]) {
12 if match_trait_method(cx, expr, &paths::ITERATOR);
13 if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), &nth_args[1]);
15 let mut applicability = Applicability::MachineApplicable;
20 "called `.nth(0)` on a `std::iter::Iterator`, when `.next()` is equivalent",
21 "try calling `.next()` instead of `.nth(0)`",
22 format!("{}.next()", snippet_with_applicability(cx, nth_args[0].span, "..", &mut applicability)),