小编neo*_*n64的帖子

在src/lib.rs我有以下

extern crate opal_core;

mod functions;
mod context;
mod shader;

然后src/context.rs我有这样的东西,它试图从src/shader.rs以下方面导入符号:

use opal_core::shader::Stage;
use opal_core::shader::Shader as ShaderTrait;
use opal_core::GraphicsContext as GraphicsContextTrait;

use functions::*; // this import works fine
use shader::*; // this one doesn't

pub struct GraphicsContext {
    functions: Gl
}

fn shader_stage_to_int(stage: &Stage) -> u32 {
    match stage {
        &Stage::Vertex => VERTEX_SHADER,
        &Stage::Geometry => GEOMETRY_SHADER,
        &Stage::Fragment => FRAGMENT_SHADER,
    }
}

impl GraphicsContextTrait for GraphicsContext {

    /// Creates a shader object
    fn create_shader(&self, stage: …

我正在尝试创建一个返回Shader特征实例的函数.这是我极为简化的代码:

trait Shader {}

struct MyShader;
impl Shader for MyShader {}

struct GraphicsContext;

impl GraphicsContext {
    fn create_shader(&self) -> Shader {
        let shader = MyShader;
        shader
    }
}

fn main() {}

但是我收到以下错误:

error[E0277]: the trait bound `Shader + 'static: std::marker::Sized` is not satisfied
  --> src/main.rs:10:32
   |
10 |     fn create_shader(&self) -> Shader {
   |                                ^^^^^^ `Shader + 'static` does not have a constant size known at compile-time
   |
   = help: the trait `std::marker::Sized` is not implemented for `Shader …

由于生命中这个令人难以置信的恼人问题,我上周一直在拔头发.

当我尝试将引用放入a Buffer内部时DataSource,会出现问题,然后引用a DrawCommand.我收到了错误:vertex_data_source活不了多久.

src/main.rs:65:23: 65:41 error: 
src/main.rs:65         data_source: &vertex_data_source
                                     ^~~~~~~~~~~~~~~~~~
src/main.rs:60:51: 67:2 note: reference must be valid for the block suffix following statement 3 at 60:50...
src/main.rs:60     let vertices = VertexAttributes::new(&buffer);
src/main.rs:61
src/main.rs:62     let vertex_data_source = factory.create_data_source(vertices);
src/main.rs:63
src/main.rs:64     let command: DrawCommand<ResourcesImpl> = DrawCommand {
src/main.rs:65         data_source: &vertex_data_source
               ...
src/main.rs:62:67: 67:2 note: ...but borrowed value is only valid for the block suffix following statement 4 at 62:66
src/main.rs:62     let vertex_data_source = factory.create_data_source(vertices); …