Macro for rust_serialize crate realized with standard macro_rule (no needs compiler features).
Add this to your `Cargo.toml`:
```toml
[dependencies]
json_macro = "*"
```
and this to your crate root:
```rust
extern crate json_macro;
```
Use macro this way:
```rust
let s = json!("string");
let f = json!(3.1f64);
let a = json!([1,2,3,4,5]);
let o = json!({
});
```