# stats_alloc
An instrumenting middleware for global allocators in Rust, useful in testing
for validating assumptions regarding allocation patterns, and potentially in
production loads to monitor for memory leaks.
## Example
```rust
extern crate stats_alloc;
use stats_alloc::{StatsAlloc, Region, INSTRUMENTED_SYSTEM};
use std::alloc::System;
#[global_allocator]
static GLOBAL: &StatsAlloc<System> = &INSTRUMENTED_SYSTEM;
fn example_using_region() {
let reg = Region::new(&GLOBAL);
let x: Vec<u8> = Vec::with_capacity(1_024);
println!("Stats at 1: {:#?}", reg.change());
// Used here to ensure that the value is not
// dropped before we check the statistics
::std::mem::size_of_val(&x);
}
```
## Custom allocators
Currenty wrapping a custom allocator requires the use of the nightly compiler
and compiling with the "nightly" feature due to the use of the unstable
`const_fn` and the fact that the internals of the instrumenting type are not
public. If that's fine with you, a custom allocator can be wrapped as follows:
```rust
#[global_allocator]
static GLOBAL: StatsAlloc<System> = StatsAlloc::new(MyCustomAllocator::new());
```