#pragma once

#include "Value.hpp"

#include <vector>

class User : public Value {
  public:
	User(const User& other) = delete;
	User(User&& other) noexcept = delete;
	User& operator=(const User& other) = delete;
	User& operator=(User&& other) noexcept = delete;
	User(Type *ty, const std::string &name = "") : Value(ty, name){}
    ~User() override;

    const std::vector<Value *> &get_operands() const { return operands_; }
    unsigned get_num_operand() const { return static_cast<unsigned>(operands_.size()); }

    // start from 0
    Value *get_operand(unsigned i) const { return operands_.at(i); }
    // start from 0
    void set_operand(unsigned i, Value *v);
    void add_operand(Value *v);

    void remove_all_operands();
    void remove_operand(unsigned i);

  private:
    std::vector<Value *> operands_; // operands of this value
};

/* For example: op = func(a, b)
 *  for a: Use(op, 0)
 *  for b: Use(op, 1)
 */
struct Use {
    User *val_;       // used by whom
    unsigned arg_no_; // the no. of operand

    Use(User *val, unsigned no) : val_(val), arg_no_(no) {}

    bool operator==(const Use &other) const {
        return val_ == other.val_ and arg_no_ == other.arg_no_;
    }
};