Function join_charsets 

pub fn join_charsets(charsets: &[&str]) -> String

Merges multiple charset strings into a single, deduplicated, and sorted string.

This function provides an enterprise-quality, build-system agnostic solution for aggregating characters for font subsetting. By combining the CHARSET constants generated natively by fluent-zero-build from your application and all its dependencies, you seamlessly compute a master charset without brittle cargo_metadata scripts or violating Cargo’s OUT_DIR sandboxing limits.

Arguments

• charsets - A slice of &str references, typically pointing to crate::CHARSET.

Returns

A deterministically sorted String containing every unique character.

Example

let complete_charset = fluent_zero::join_charsets(&[
    crate::CHARSET,
    my_ui_lib::CHARSET,
]);
std::fs::write("target/font_charset.txt", complete_charset).unwrap();