derive neg for quantity

Cargo.toml

@@ -88,7 +88,7 @@ version = "1.0.*"
 [workspace.dependencies.derive_more]
 version = "2.1.*"
 default-features = false
-features = ["add", "add_assign", "display"]
+features = ["add", "add_assign", "neg", "display"]
 [workspace.dependencies.thiserror]
 version = "2.0.*"
 default-features = false

generate-quantity/src/lib.rs

@@ -4,7 +4,7 @@ use proc_macro2::{Span, TokenStream as TokenStream2};
 use quote::quote;
 use std::ops::Deref;
 use syn::parse::{Parse, ParseStream};
-use syn::{parse_macro_input, Ident, LitStr, Token};
+use syn::{Ident, LitStr, Token, parse_macro_input};
 
 const NUMBER_TYPES: &[&str] = &[
     "u8", "i8", "u16", "i16", "u32", "i32", "u64", "i64", "u128", "i128", "usize", "isize", "f32",
@@ -108,6 +108,7 @@ pub fn quantity_type(input: TokenStream) -> TokenStream {
             derive_more::AddAssign,
             derive_more::Sub,
             derive_more::SubAssign,
+            derive_more::Neg,
             derive_more::Display
         )]
         #[display("{_0} {}", Self::symbol())]