private Action<object, object> GetFieldSetter()
{
var fieldInfo = (FieldInfo)_memberInfo;
if (IsReadOnly)
{
var message = string.Format(
"The field '{0} {1}' of class '{2}' is readonly. To avoid this exception, call IsReadOnly to ensure that setting a value is allowed.",
fieldInfo.FieldType.FullName, fieldInfo.Name, fieldInfo.DeclaringType.FullName);
throw new BsonSerializationException(message);
}
var sourceType = fieldInfo.DeclaringType;
var method = new DynamicMethod("Set" + fieldInfo.Name, null, new[] { typeof(object), typeof(object) }, true);
var gen = method.GetILGenerator();
gen.Emit(OpCodes.Ldarg_0);
gen.Emit(OpCodes.Castclass, sourceType);
gen.Emit(OpCodes.Ldarg_1);
gen.Emit(OpCodes.Unbox_Any, fieldInfo.FieldType);
gen.Emit(OpCodes.Stfld, fieldInfo);
gen.Emit(OpCodes.Ret);
return (Action<object, object>)method.CreateDelegate(typeof(Action<object, object>));
}