Improve ternary if expression type inference rues

Allow for expression like this

    `x: union{f32} = f32(123) if cond else nil`

1 files changed, 11 insertions, 2 deletions

diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index df293e955..27efbc9ae 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -7518,16 +7518,25 @@ gb_internal ExprKind check_ternary_if_expr(CheckerContext *c, Operand *o, Ast *n
 		return kind;
 	}
 
-	convert_to_typed(c, &x, y.type);
+	convert_to_typed(c, &x, type_hint ? type_hint : y.type);
 	if (x.mode == Addressing_Invalid) {
 		return kind;
 	}
-	convert_to_typed(c, &y, x.type);
+	convert_to_typed(c, &y, type_hint ? type_hint : x.type);
 	if (y.mode == Addressing_Invalid) {
 		x.mode = Addressing_Invalid;
 		return kind;
 	}
 
+	// NOTE(bill, 2023-01-30): Allow for expression like this:
+	//     x: union{f32} = f32(123) if cond else nil
+	if (type_hint && !ternary_compare_types(x.type, y.type)) {
+		if (check_is_assignable_to(c, &x, type_hint) && check_is_assignable_to(c, &y, type_hint)) {
+			check_cast(c, &x, type_hint);
+			check_cast(c, &y, type_hint);
+		}
+	}
+
 	if (!ternary_compare_types(x.type, y.type)) {
 		gbString its = type_to_string(x.type);
 		gbString ets = type_to_string(y.type);