You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: time.rs
    path of file: ./repos/wgpu/wgpu-hal/src/auxil/dxgi
    
    the code of the file until where you have to start completion: #![allow(dead_code)] // IPresentationManager is unused currently

use std::mem;

use winapi::um::{
    profileapi::{QueryPerformanceCounter, QueryPerformanceFrequency},
    winnt::LARGE_INTEGER,
};

pub enum PresentationTimer {
    /// DXGI uses QueryPerformanceCounter
    Dxgi {
        /// How many ticks of QPC per second
        frequency: u64,
    }
    
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match *self {
            Self::Dxgi { frequency } => f
                .debug_struct("DXGI")
                .field("frequency", &frequency)
                .finish(),
            Self::IPresentationManager {
                fnQueryInterruptTimePrecise,
            } => f
                .debug_struct("IPresentationManager")
                .field(
                    "QueryInterruptTimePrecise",
                    &(fnQueryInterruptTimePrecise as usize),
                )
                .finish(),
        }
    }