/// # Supported output types
///
/// - `Expr`
/// - `Pat`
/// - `Stmt`
/// - `ModuleItem`
///
/// - Option<T> where T is supported type
/// - Box<T> where T is supported type
///
/// For example, `Box<Expr>` and `Option<Box<Expr>>` are supported.
///
/// # Variable substitution
///
/// If an identifier starts with `$`, it is substituted with the value of the
/// parameter passed.
///
/// e.g.
///
/// ```rust
/// use swc_common::DUMMY_SP;
/// use swc_ecma_ast::Ident;
/// use swc_ecma_quote::quote;
///
/// // This will return ast for `const ref = 4;`
/// let _stmt = quote!("const $name = 4;" as Stmt, name = Ident::new("ref".into(), DUMMY_SP));
///
/// // Tip: Use private_ident!("ref") for real identifiers.
/// ```
///
/// ## Typed variables
///
/// As this macro generates static AST, it can't substitute variables if an
/// ideitifier is not allowed in such position. In other words, this macro only
/// supports substituting
///
/// - Ident
/// - Expr
/// - Pat
///
/// You can use it like
///
/// ```rust
/// use swc_common::DUMMY_SP;
/// use swc_ecma_ast::Ident;
/// use swc_ecma_quote::quote;
///
/// // This will return ast for `const ref = 4;`
/// let _stmt = quote!(
/// "const $name = $val;" as Stmt,
/// name = Ident::new("ref".into(), DUMMY_SP),
/// val: Expr = 4.into(),
/// );
/// ```
///
/// # Examples
///
/// ## Quote a variable declaration
/// ```rust
/// use swc_common::DUMMY_SP;
/// use swc_ecma_ast::Ident;
/// use swc_ecma_quote::quote;
///
/// // This will return ast for `const ref = 4;`
/// let _stmt = quote!("const $name = 4;" as Stmt, name =
/// Ident::new("ref".into(), DUMMY_SP));
///
/// // Tip: Use private_ident!("ref") for real identifiers.
/// ```
/// Creates a `Box<Expr>` from the source code.
///
/// This is an alias for [quote], but without `as Box<Expr>`.
/// Noop