Brainfuck interpreter in C++11

bf.cpp

#include <algorithm>
#include <functional>
#include <iostream>
#include <fstream>
#include <unordered_map>
#include <vector>

// byte array
using Memory = std::vector<unsigned char>;
using Pointer = Memory::iterator;


auto read_program(const char* path) {
    Memory imem;
    std::ifstream fin(path);
    if (fin) {
        std::copy(std::istreambuf_iterator<char>(fin),
                  std::istreambuf_iterator<char>(),
                  std::back_inserter(imem));
    } else {
        std::cerr << "file: " << path << " not found" << std::endl;
    }
    return std::move(imem);
}

int main(int argc, char* argv[]) {
    std::cin.unsetf(std::ios_base::skipws);
    std::ios_base::sync_with_stdio(false);
    if (argc != 2) {
        std::cerr << "usage: " << argv[0] << " <bf file>" << std::endl;
    }

    Memory imem = read_program(argv[1]);
    Memory dmem(65536);
    auto iptr = imem.begin();
    auto dptr = dmem.begin();
    std::unordered_map<char, std::function<void()>> actions = {
        {'>', [&]{ ++dptr; }},
        {'<', [&]{ --dptr; }},
        {'+', [&]{ ++(*dptr); }},
        {'-', [&]{ --(*dptr); }},
        {'.', [&]{ std::cout << *dptr; }},
        {',', [&]{ std::cin >> *dptr; }},
        {'[', [&]{
                if (!*(dptr)) {
                    for (int t = 1; t; ++iptr) {
                        if (*iptr == '[') { ++t; }
                        else if (*iptr == ']') { --t; }
                    }
                }
            }
        },
        {']', [&]{
                iptr -= 2;
                for (int t = -1; t; --iptr) {
                    if (*iptr == '[') { ++t; }
                    else if (*iptr == ']') { --t; }
                }
                ++iptr;
            }}
    };

    while (iptr != imem.end()) {
        if (auto f = actions[*iptr++]) {
            f();
        }
    }
}

hello.bf

>+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-]>++++++++[<++
++>-]<.>+++++++++++[<+++++>-]<.>++++++++[<+++>-]<.+++.------.--------.[-]>
++++++++[<++++>-]<+.[-]++++++++++.