显式生存期更改函数签名,并使函数与所需的类型签名不兼容

#![feature(rustc_private)]
#![feature(box_syntax)]
extern crate rustc;
extern crate rustc_driver;

use rustc::hir::intravisit as hir_visit;
use rustc::hir;
use rustc_driver::driver::{CompileController, CompileState};

pub struct SomeVisitor<'a, 'tcx: 'a> {
    pub map: &'a hir::map::Map<'tcx>,
}

impl<'v, 'tcx: 'v> rustc::hir::intravisit::Visitor<'tcx> for SomeVisitor<'v, 'tcx> {
    fn nested_visit_map<'this>(&'this mut self) -> hir_visit::NestedVisitorMap<'this, 'tcx> {
        hir_visit::NestedVisitorMap::All(self.map)
    }
}

fn hir(s: &mut CompileState) {
    let krate = s.hir_crate.unwrap();
    let map = s.hir_map.unwrap();
    let mut visitor = SomeVisitor { map };
    hir_visit::walk_crate(&mut visitor, krate);
}

fn main() {
    {
        let mut controller = CompileController::basic();
        controller.after_hir_lowering.callback = box hir;
    }
}

playground

我理解为什么会出现生存期错误,通过为函数添加显式生存期很容易解决它 hir .

pub fn walk_crate<'v, V: hir_visit::Visitor<'v>>(visitor: &mut V, krate: &'v Crate) {}

'tcx .

fn hir<'v, 'tcx>(s: &'tcx mut CompileState<'v, 'tcx>) {
    let krate = s.hir_crate.unwrap();
    let map = s.hir_map.unwrap();
    let mut visitor = SomeVisitor { map };
    hir_visit::walk_crate(&mut visitor, krate);
}

hir公司 与回调不兼容。 playground

HRTB

更新:

playground