Language: C++

#define NDEBUG
#include <cassert>
#include <cstdint>
#include <functional>
#include <vector>

template <typename Abelian> class FenwickTree {
	using uint32 = std::uint_fast32_t;

public:
	using value_type = Abelian;
	using reference = Abelian &;
	using const_reference = const Abelian &;

private:
	using F = std::function<value_type(const_reference, const_reference)>;
	const value_type neutral_;
	const F p, m;
	const uint32 size_;
	std::vector<value_type> tree;
	static uint32 getsize(const uint32 size) {
		uint32 ret = 1;
		while (ret < size)
			ret <<= 1;
		return ret;
	}

public:
	FenwickTree(const uint32 size, const_reference neutral = value_type(),
		const F &p = std::plus<value_type>(),
		const F &m = std::minus<value_type>())
		: neutral_(neutral), p(p), m(m), size_(getsize(size)),
		tree(size_ + 1, neutral_) {}
	FenwickTree(const uint32 size, const_reference neutral, const F &p,
		const std::function<value_type(const_reference)> &n)
		: neutral_(neutral), p(p),
		m([&p, &n](const_reference l, const_reference r) {
		return p(l, n(r));
	}),
		size_(getsize(size)), tree(size_ + 1, neutral_) {}
	void update(uint32 index, const std::function<void(reference)> &g) {
		assert(index < size_);
		++index;
		const value_type a = tree[index];
		g(tree[index]);
		const_reference b = tree[index];
		while ((index += index & ~index + 1) <= size_)
			tree[index] = p(m(tree[index], a), b);
	}
	void update(uint32 index, const_reference data) {
		update(index, [&data](reference d) { d = data; });
	}
	void add(uint32 index, const_reference diff) {
		assert(index < size_);
		for (++index; index <= size_; index += index & ~index + 1)
			tree[index] = p(tree[index], diff);
	}
	value_type range(uint32 end) const {
		assert(end <= size_);
		value_type ret = neutral_;
		do
			ret = p(tree[end], ret);
		while (end &= end - 1);
		return ret;
	}
	value_type range(uint32 begin, uint32 end) const {
		assert(begin <= end);
		return m(range(end), range(begin));
	}
	uint32 search(const std::function<bool(const_reference)> &b) const {
		if (!b(tree.back()))
			return size_;
		uint32 i = size_ >> 1;
		value_type acc = neutral;
		for (uint32 k = size_ >> 1; k; k >>= 1)
			if (!b(p(acc, tree[i -= k])))
				acc = p(acc, tree[i]), i += k;
		return i - 1;
	}
	value_type operator[](uint32 index) const {
		assert(index < size_);
		return range(index, index + 1);
	}
};

//#define NDEBUG
#define _CRT_SECURE_NO_WARNINGS
#include <algorithm>
#include <array>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <functional>
#include <limits>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
constexpr double PI = 3.1415926535897932;

using int32 = std::int_fast32_t;
using int64 = std::int_fast64_t;
using uint32 = std::uint_fast32_t;
using uint64 = std::uint_fast64_t;
using intl32 = std::int_least32_t;
using intl64 = std::int_least64_t;
using uintl32 = std::uint_least32_t;
using uintl64 = std::uint_least64_t;

const char *yes(bool c) { return c ? "yes" : "no"; }
const char *Yes(bool c) { return c ? "Yes" : "No"; }
const char *YES(bool c) { return c ? "YES" : "NO"; }
const char *pos(bool c) { return c ? "possible" : "impossible"; }
const char *Pos(bool c) { return c ? "Possible" : "Impossible"; }
const char *POS(bool c) { return c ? "POSSIBLE" : "IMPOSSIBLE"; }
template<class T>bool bmaxi(T&a, const T&b) { if (b<a)return 0;a = b;return 1; }
template<class T>bool bmini(T&a, const T&b) { if (a<b)return 0;a = b;return 1; }
template<class T>bool nmaxi(T&a, const T&b) { if (a<b) { a = b;return 1; }return 0; }
template<class T>bool nmini(T&a, const T&b) { if (b<a) { a = b;return 1; }return 0; }
template<typename T>auto scan(T&d)->typename std::enable_if<std::is_signed<T>::value>::type
{
	d = 0;int c = fgetc(stdin);bool f = 0;while (c<'0' || '9'<c) { if (c == '-')f = 1;c = fgetc(stdin); }
	while (c != ' '&&c != '\n') { d = d * 10 + c - '0';c = fgetc(stdin); }if (f)d = -d;
}
template<typename T>auto scan(T&d)->typename std::enable_if<!std::is_signed<T>::value>::type
{
	d = 0;int c = fgetc(stdin);while (c == ' ' || c == '\n')c = fgetc(stdin);
	while (c != ' '&&c != '\n') { d = d * 10 + c - '0';c = fgetc(stdin); }
}
void scan(char&d) { d = fgetc(stdin);while (d == ' ' || d == '\n')d = fgetc(stdin); }
void scan(double&d) { scanf("%lf", &d); }void scan(std::string&d) {
	d.clear();int c = fgetc(stdin);
	while (c == ' ' || c == '\n')c = fgetc(stdin);while (c != ' '&&c != '\n') { d.push_back(c);c = fgetc(stdin); }
}
template<typename F, typename...R>void scan(F&f, R&...r) { scan(f);scan(r...); }
template<typename T>T input() { T d;scan(d);return d; }
template <typename T>auto print(T d)->typename std::enable_if<std::is_signed<T>::value>::type
{
	static int c[20];int i = 0;bool f = 0;if (d<0) { f = 1;d = -d; }while (d) { c[i++] = d % 10;d /= 10; }
	if (!i)c[i++] = 0;if (f)fputc('-', stdout);while (i--)fputc(c[i] + '0', stdout);
}
template<typename T>auto print(T d)->typename std::enable_if<!std::is_signed<T>::value>::type
{
	static int c[20];int i = 0;while (d) { c[i++] = d % 10;d /= 10; }
	if (!i)c[i++] = 0;while (i--)fputc(c[i] + '0', stdout);
}
template<>void print<char>(char d) { fputc(d, stdout); }
template<>void print<double>(double d) { printf("%f", d); }
template<>void print<char *>(char *c) { while (*c != '\0')fputc(*(c++), stdout); }void print() {}
template<typename F, typename...R>void print(F f, R...r) { print(f);print(r...); }
template<typename...R>void println(R...r) { print(r...);fputc('\n', stdout); }
template<typename...R>int END(R...r) { println(r...);return 0; }
int main(void) {
	uint32 n, q;
	scan(n, q);
	FenwickTree<uint32> T(n, 0);
	while (q--) {
		uint32 c, x, y;
		scan(c, x, y);
		if (c) {
			println(T.range(x - 1, y));
		}
		else {
			T.update(x - 1, [&](uint32 &d) {d += y;});
		}
	}
	return 0;
}


Compiler output:
a.cc: In member function 'FenwickTree<Abelian>::uint32 FenwickTree<Abelian>::search(const std::function<bool(const Abelian&)>&) const':
a.cc:74:34: error: 'neutral' was not declared in this scope; did you mean 'neutral_'?
   74 |                 value_type acc = neutral;
      |                                  ^~~~~~~
      |                                  neutral_