std::numeri...x_exponent10(3)

💖 NAME 💖

std::numeric_limits::max_exponent10 — std::numeric_limits::max_exponent10

okay so bestie, welcome to the C++ Standard Libary manual — yes, that’s the manual name, spelling and all 💅 — and today’s main character is std::numeric_limits::max_exponent10. It’s giving very specific floating-point limit energy, and we’re gonna understand it fr fr. 🦋

✨ Synopsis ✨

Here’s the signature tea ☕:

static const int max_exponent10;      (until C++11)
static constexpr int max_exponent10;  (since C++11)

The value of std::numeric_limits<T>::max_exponent10 is the largest positive number n such that 10^n is a representable finite value of the floating-point type T. 🌸

👑 Standard specializations 👑

For each T, here’s the value of std::numeric_limits<T>::max_exponent10 — no cap, this is the whole roster:

• /* non-specialized */ — 0
• bool — 0
• char — 0
• signed char — 0
• unsigned char — 0
• wchar_t — 0
• char8_t (since C++20) — 0
• char16_t (since C++11) — 0
• char32_t (since C++11) — 0
• short — 0
• unsigned short — 0
• int — 0
• unsigned int — 0
• long — 0
• unsigned long — 0
• long long (since C++11) — 0
• unsigned long long (since C++11) — 0
• float — FLT_MAX_10_EXP
• double — DBL_MAX_10_EXP
• long double — LDBL_MAX_10_EXP

bestie, notice how all the non-specialized and integer-ish types are sitting at 0 — that’s not a typo, that’s literally the table. 💅

🎀 Example 🎀

Demonstrates the relationships of max_exponent, max_exponent10, and max() for the type float:

// Run this code

#include <iostream>
#include <limits>

int main()
{
    std::cout << "max() = " << std::numeric_limits<float>::max() << '\n'
              << "max_exponent10 = " << std::numeric_limits<float>::max_exponent10 << '\n'
              << std::hexfloat << '\n'
              << "max() = " << std::numeric_limits<float>::max() << '\n'
              << "max_exponent = " << std::numeric_limits<float>::max_exponent << '\n';
}

🌈 Output 🌈

max() = 3.40282e+38
max_exponent10 = 38

max() = 0x1.fffffep+127
max_exponent = 128

👀 See also 👀

Go peek at these too, iykyk:

• max_exponent [static] — one more than the largest integer power of the radix that is a valid finite floating-point value (public static member constant)
• min_exponent [static] — one more than the smallest negative power of the radix that is a valid normalized floating-point value (public static member constant)
• min_exponent10 [static] — the smallest negative power of ten that is a valid normalized floating-point value (public static member constant)

That’s the whole page, bestie 🫶 — source: http://cppreference.com, version/date: 2024.06.10. Slay and stay numeric 💜✨