C++14 adds the ability to write numbers with digit separators for better readability. Splitting a number that has more than 4 consecutive digits
improves readability.

This rule verifies that numbers are written using digit separators when they have more than 4 consecutive digits.

## Noncompliant Code Example

long decimal_int_value = 5543124; // Noncompliant; insert ' between groups of 3 digits.
double decimal_float_value = 7918714.3456; // Noncompliant; insert ' between groups of 3 digits.
long hexadecimal_value = 0x83A32486E2; // Noncompliant; insert ' between groups of 2 or 4 digits.
long octal_value = 04420343313726; // Noncompliant; insert ' between groups of 2, 3 or 4 digits.
long binary_value = 0b0101011011101010; // Noncompliant; insert ' between groups of 2, 3 or 4 digits.

## Compliant Solution

long decimal_int_value = 5'543'124;
double decimal_float_value = 7'918'714.3456;
long hexadecimal_value = 0x83'A324'86E2;
long octal_value = 04'4203'4331'3726;
long binary_value = 0b0101'0110'1110'1010;

## Exceptions

No issue is raised on the fractional or exponent part of floating point numbers, only the integral part should comply.