tests: use isreftype[T]() and sizeof[T]() syntax, fix vfmt to support them, when written explicitly (#17103)

vlib/v/fmt/fmt.v

@@ -2637,17 +2637,17 @@ pub fn (mut f Fmt) selector_expr(node ast.SelectorExpr) {
 
 pub fn (mut f Fmt) size_of(node ast.SizeOf) {
 	f.write('sizeof')
-	if node.is_type {
-		// keep the old form for now
-		f.write('(')
-		f.write(f.table.type_to_str_using_aliases(node.typ, f.mod2alias))
-		f.write(')')
-		return
-	}
-	if node.is_type {
+	if node.is_type && !node.guessed_type {
+		// the new form was explicitly written in the source code; keep it:
 		f.write('[')
 		f.write(f.table.type_to_str_using_aliases(node.typ, f.mod2alias))
 		f.write(']()')
+		return
+	}
+	if node.is_type {
+		f.write('(')
+		f.write(f.table.type_to_str_using_aliases(node.typ, f.mod2alias))
+		f.write(')')
 	} else {
 		f.write('(')
 		f.expr(node.expr)
@@ -2657,17 +2657,17 @@ pub fn (mut f Fmt) size_of(node ast.SizeOf) {
 
 pub fn (mut f Fmt) is_ref_type(node ast.IsRefType) {
 	f.write('isreftype')
-	if node.is_type {
-		// keep the old form for now
-		f.write('(')
-		f.write(f.table.type_to_str_using_aliases(node.typ, f.mod2alias))
-		f.write(')')
-		return
-	}
-	if node.is_type {
+	if node.is_type && !node.guessed_type {
+		// the new form was explicitly written in the source code; keep it:
 		f.write('[')
 		f.write(f.table.type_to_str_using_aliases(node.typ, f.mod2alias))
 		f.write(']()')
+		return
+	}
+	if node.is_type {
+		f.write('(')
+		f.write(f.table.type_to_str_using_aliases(node.typ, f.mod2alias))
+		f.write(')')
 	} else {
 		f.write('(')
 		f.expr(node.expr)

vlib/v/tests/isreftype_test.v

@@ -29,8 +29,8 @@ fn test_isreftype() {
 	assert isreftype(S4) == false
 	assert isreftype(S5) == true
 	assert isreftype(f64) == false
-	assert isreftype([]f64) == true
-	assert isreftype([3]int) == false
+	assert isreftype[[]f64]() == true
+	assert isreftype[[3]int]() == false
 }
 
 fn check_ref[T]() string {

vlib/v/tests/sizeof_test.v

@@ -16,7 +16,7 @@ fn test_math_sizeof() {
 
 fn test_sizeof() {
 	assert sizeof(rune) == 4
-	assert sizeof([44]u8) == 44
+	assert sizeof[[44]u8]() == 44
 	assert sizeof(`€`) == 4
 	// depends on -m32/64
 	assert sizeof(S1) in [u32(4), 8]