1 files changed, 34 insertions, 0 deletions
diff --git a/src/tools/rust-analyzer/crates/ide-db/src/use_trivial_contructor.rs b/src/tools/rust-analyzer/crates/ide-db/src/use_trivial_contructor.rs
new file mode 100644
index 000000000..39431bed3
--- /dev/null
+++ b/src/tools/rust-analyzer/crates/ide-db/src/use_trivial_contructor.rs
@@ -0,0 +1,34 @@
+//! Functionality for generating trivial contructors
+
+use hir::StructKind;
+use syntax::ast;
+
+/// given a type return the trivial contructor (if one exists)
+pub fn use_trivial_constructor(
+    db: &crate::RootDatabase,
+    path: ast::Path,
+    ty: &hir::Type,
+) -> Option<ast::Expr> {
+    match ty.as_adt() {
+        Some(hir::Adt::Enum(x)) => {
+            if let &[variant] = &*x.variants(db) {
+                if variant.kind(db) == hir::StructKind::Unit {
+                    let path = ast::make::path_qualified(
+                        path,
+                        syntax::ast::make::path_segment(ast::make::name_ref(
+                            &variant.name(db).to_smol_str(),
+                        )),
+                    );
+
+                    return Some(syntax::ast::make::expr_path(path));
+                }
+            }
+        }
+        Some(hir::Adt::Struct(x)) if x.kind(db) == StructKind::Unit => {
+            return Some(syntax::ast::make::expr_path(path));
+        }
+        _ => {}
+    }
+
+    None
+}