Language: C++

#define _CRT_SECURE_NO_WARNINGS
#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#define rep(i, n) for(int i=0;i<(n);i++)
#define REP(i, n) for(int i=1;i<=(n);i++)
#define all(V) V.begin(),V.end()
typedef long long lint;
typedef std::pair<lint, lint> P;
constexpr int INF = INT_MAX;
constexpr lint LINF = LLONG_MAX;
constexpr double eps = 1e-9;
template<class T>
class prique :public std::priority_queue<T, std::vector<T>, std::greater<T>> {};
template <class T, class U>
inline bool chmax(T& lhs, const U& rhs) {
	if (lhs < rhs) {
		lhs = rhs;
		return 1;
	}
	return 0;
}
template <class T, class U>
inline bool chmin(T& lhs, const U& rhs) {
	if (lhs > rhs) {
		lhs = rhs;
		return 1;
	}
	return 0;
}
inline lint gcd(lint a, lint b) {
	while (b) {
		lint c = a;
		a = b; b = c % b;
	}
	return a;
}
inline lint lcm(lint a, lint b) {
	return a / gcd(a, b) * b;
}
bool isprime(lint n) {
	if (n == 1)return false;
	for (int i = 2; i * i <= n; i++) {
		if (n % i == 0)return false;
	}
	return true;
}
lint mypow(lint a, lint b) {
	if (!b)return 1;
	if (b & 1)return mypow(a, b - 1) * a;
	lint memo = mypow(a, b >> 1);
	return memo * memo;
}
lint modpow(lint a, lint b, lint m) {
	if (!b)return 1;
	if (b & 1)return modpow(a, b - 1, m) * a % m;
	lint memo = modpow(a, b >> 1, m);
	return memo * memo % m;
}
void printArray(std::vector<int>& vec) {
	rep(i, vec.size() - 1)std::cout << vec[i] << " ";
	std::cout << vec.back() << std::endl;
}
template<typename T>
void printArray(T l, T r) {
	T rprev = r;
	rprev--;
	for (T i = l; i != rprev; i++) {
		std::cout << *i << " ";
	}
	std::cout << *rprev << std::endl;
}
std::string to_string(std::vector<int>& vec) {
	std::string res = "[";
	rep(i, vec.size() - 1)res += std::to_string(vec[i]) + ", ";
	res += std::to_string(vec.back()) + "]";
	return res;
}
template<class T, class Allocator = std::allocator<T>>
class vector {

	using traits = std::allocator_traits<std::allocator<T>>;

private:

	T* e = nullptr;
	unsigned int length = 0, cap = 1;
	Allocator alloc;

	static_assert(std::is_same<T, Allocator::value_type>::value, "The allocator value type is not matched the vector value type.");
	static_assert(!std::is_const<T>::value, "The C++ Standard forbids containers of const elements");

public:

	vector() :vector(Allocator()) {}

	explicit vector(const Allocator& a) :alloc(a) {
		e = alloc.allocate(cap);
	}

	explicit vector(unsigned int n, const Allocator& a = Allocator()) :alloc(a) {
		while (cap < n)cap *= 2;
		e = alloc.allocate(cap);
	}

	explicit vector(unsigned int n, const T& value = T(), const Allocator& a = Allocator()) :alloc(a) {
		while (cap < n)cap *= 2;
		e = alloc.allocate(cap);
		std::fill(e, e + n, value);
	}

	template<class InputIter>
	vector(InputIter first, InputIter last, const Allocator& a = Allocator()) :alloc(a) {
		for (InputIter i = first; i != last; i++) {
			emplace_back(*i);
		}
	}

	vector(const vector& x) :vector(x, Allocator()) {}

	vector(vector&& x) :vector(x, Allocator()) {}

	vector(const vector& x, const Allocator& a) :alloc(a) {
		while (cap < x.length)cap *= 2;
		e = alloc.allocate(cap);
		std::copy(x.e, x.e + x.length, e);
	}

	vector(vector&& x, const Allocator& a) :alloc(a) {
		while (cap < x.length)cap *= 2;
		e = alloc.allocate(cap);
		std::move(x.e, x.e + x.length, e);
	}

private:

	void extension() {
		T* e_ = alloc.allocate(cap * 2);
		std::move(e, e + length, e_);
		alloc.deallocate(e, cap);
		e = e_;
		cap *= 2;
	}

public:

	template<class... Args>
	void emplace_back(Args&&... args) {
		if (length == cap)extension();
		traits::construct(alloc, e + length, std::forward<Args>(args)...);
		length++;
	}

	unsigned int size() {
		return length;
	}

	unsigned int capacity() {
		return cap;
	}

	T& operator[](const unsigned int pos) {
		return e[pos];
	}

	T* data() {
		return e;
	}

	T* front() {
		return e;
	}

	T* back() {
		return e + length - 1;
	}
};
signed main() {
	std::string s;
	std::cin >> s;
	if (s[0] == '7'||s[1] == '7' || s[2] == '7')puts("Yes");
	else puts("No");
	return 0;
}

Compiler output:
a.cc:115:60: error: to refer to a type member of a template parameter, use 'typename Allocator::value_type' [-fpermissive]
  115 |         static_assert(std::is_same<T, Allocator::value_type>::value, "The allocator value type is not matched the vector value type.");
      |                                                            ^