type_resolver: support $if T is $pointer { and $if T is $voidptr {, to make it easier to implement a pure V dump(), without cgen specific code (#24628)

Author: spytheman

vlib/v/ast/ast.v

@@ -162,6 +162,8 @@ pub enum ComptimeTypeKind {
 	function
 	option
 	string
+	pointer
+	voidptr
 }
 
 pub struct ComptimeType {
@@ -187,6 +189,8 @@ pub fn (cty ComptimeType) str() string {
 		.function { '\$function' }
 		.option { '\$option' }
 		.string { '\$string' }
+		.pointer { '\$pointer' }
+		.voidptr { '\$voidptr' }
 	}
 }
 

vlib/v/fmt/fmt.v

@@ -800,6 +800,8 @@ pub fn (mut f Fmt) expr(node_ ast.Expr) {
 				.function { f.write('\$function') }
 				.option { f.write('\$option') }
 				.string { f.write('\$string') }
+				.pointer { f.write('\$pointer') }
+				.voidptr { f.write('\$voidptr') }
 			}
 		}
 	}

vlib/v/gen/golang/golang.v

@@ -677,6 +677,8 @@ pub fn (mut f Gen) expr(node_ ast.Expr) {
 				.function { f.write('\$function') }
 				.option { f.write('\$option') }
 				.string { f.write('\$string') }
+				.pointer { f.write('\$pointer') }
+				.voidptr { f.write('\$voidptr') }
 			}
 		}
 	}

vlib/v/parser/comptime.v

@@ -10,7 +10,7 @@ import v.token
 const supported_comptime_calls = ['html', 'tmpl', 'env', 'embed_file', 'pkgconfig', 'compile_error',
 	'compile_warn', 'd', 'res']
 const comptime_types = ['map', 'array', 'array_dynamic', 'array_fixed', 'int', 'float', 'struct',
-	'interface', 'enum', 'sumtype', 'alias', 'function', 'option', 'string']
+	'interface', 'enum', 'sumtype', 'alias', 'function', 'option', 'string', 'pointer', 'voidptr']
 
 fn (mut p Parser) parse_comptime_type() ast.ComptimeType {
 	pos := p.tok.pos()
@@ -63,6 +63,12 @@ fn (mut p Parser) parse_comptime_type() ast.ComptimeType {
 		'string' {
 			.string
 		}
+		'pointer' {
+			.pointer
+		}
+		'voidptr' {
+			.voidptr
+		}
 		else {
 			.unknown
 		}

vlib/v/tests/comptime/comptime_if_is_pointer_test.v

@@ -0,0 +1,37 @@
+fn g[T](x T, is_pointer bool, is_voidptr bool) {
+	println('type: ${typeof[T]().name}, isreftype(T): ${isreftype(T)}')
+	$if T is $pointer {
+		println('T is \$pointer')
+		assert is_pointer
+	} $else {
+		println('T is NOT a \$pointer')
+		assert !is_pointer
+	}
+	$if T is $voidptr {
+		println('T is \$voidptr')
+		assert is_voidptr
+	} $else {
+		println('T is NOT a \$voidptr')
+		assert !is_voidptr
+	}
+	println('--------------------------')
+}
+
+struct Abc {}
+
+fn test_is_pointer_and_is_voidptr() {
+	unsafe {
+		g(voidptr(123), true, true)
+		g(&char(456), true, false)
+		//
+		g(int(1000), false, false)
+		g(&int(1001), true, false)
+		g(&&int(1002), true, false)
+		g(&&&int(1003), true, false)
+		//
+		g(Abc{}, false, false)
+		g(&Abc(10001), true, false)
+		g(&&Abc(10002), true, false)
+		g(&&&Abc(10003), true, false)
+	}
+}

vlib/v/type_resolver/comptime_resolver.v

@@ -249,6 +249,12 @@ pub fn (t &TypeResolver) is_comptime_type(x ast.Type, y ast.ComptimeType) bool {
 		.string {
 			return x_kind == .string
 		}
+		.voidptr {
+			return x.is_voidptr()
+		}
+		.pointer {
+			return x.is_any_kind_of_pointer()
+		}
 		.int {
 			return x_kind in [.i8, .i16, .i32, .int, .i64, .u8, .u16, .u32, .u64, .usize, .isize,
 				.int_literal]