feat: add ParseAs and NewSchema generics

Assisted-by: GLM 5.3 Flash

interpres_test.go

@@ -8,6 +8,7 @@ import (
 	"math"
 	"os"
 	"path/filepath"
+	"reflect"
 	"strings"
 	"testing"
 	"time"
@@ -773,3 +774,25 @@ func TestValid(t *testing.T) {
 		t.Errorf("Valid(invalid) = %v, want a SyntaxError", err)
 	}
 }
+
+func TestParseAsAndNewSchema(t *testing.T) {
+	type Config struct {
+		Host string `toml:"host"`
+		Port int    `toml:"port"`
+	}
+	cfg, err := ParseAs[Config]([]byte("host = \"db\"\nport = 5432\n"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.Host != "db" || cfg.Port != 5432 {
+		t.Errorf("decoded %+v", cfg)
+	}
+	if _, err := ParseAs[Config]([]byte("port =\n")); err == nil {
+		t.Error("ParseAs(invalid) succeeded, want an error and the zero value")
+	}
+	NewSchema[Config]()
+	if _, ok := structSchemaCache.Load(reflect.TypeFor[Config]()); !ok {
+		t.Error("NewSchema left no schema in the cache")
+	}
+	NewSchema[map[string]any]() // must not panic
+}