How to protect enum assignment

I want to prevent invalid value enum assigment. I know if i even assign value that is not in enum it will work. Example:

enum example_enum
{
    ENUM_VAL0,
    ENUM_VAL1,
    ENUM_VAL2,
    ENUM_VAL3
};

void example_function(void)
{
  enum example_enum the_enum = ENUM_VAL3; // correct
  the_enum = 12345; // will work
  bar(the_enum); // this function assumes that input parameter is correct
}

Is there easy, efficient way to check if assignment to enum is correct? I could test value by function

void foo(enum example_enum the_enum)
{
  if (!is_enum(the_enum))
    return;

  // do something with valid enum
}

I could resolve this in following way:

static int e_values[] = { ENUM_VAL0, ENUM_VAL1, ENUM_VAL2, ENUM_VAL3 };
int is_enum(int input)
{
  for (int i=0;i<4;i++)
    if (e_values[i] == input)
      return 1;
  return 0;
}

For me, my solution is inefficient, how can i write this if i have more enums and more values in enums?