boost::algorithm::one_of_equal() in C++ library

The function boost::algorithm::one_of_equal() is a Boost String Algorithms library feature. Its purpose is to determine whether a given string contains any characters. It checks if a string has at one occurrence of any character we provide as input.

To illustrate this, let's suppose we have a string called my_string, and we want to verify if it includes any vowel characters 'a' 'e', 'i', 'o', or 'u'. Here's how we would do it;

In the code snippet, we call boost::algorithm::one_of_equal() and pass my_string along with a string containing the vowel characters "aeiou" as parameters.

If my_string contains one of those characters, the function will return true. Since my_str, ing includes both 'e' and 'o', it will return true. It displays the message "my_string has a vowel".

The one_of_equal() function takes two parameters:

1. The input string to search in
2. The set of characters to search for

It returns a bool indicating if the input string contains atleast one occurrence of any of the characters we are searching for.

Some important points to keep in mind about the function called "one_of_equal()":

• It distinguishes between uppercase and lowercase It means that 'a' and 'A' are treated as characters.
• The set of characters we seek can be provided as a string, a vector of characters, a C string, or any other iterable format.
• It also works for strings (wstring) in the way.
• If the string being searched is empty, it will always give a result.
• Similarly, if the search set is empty, it will always give a result.

It can be useful for tasks like:

• Checking if a string has vowels.
• Checking if a password is strong enough.
• Checking if a string contains special characters.

The Boost String Algorithms library contains many other useful functions like trim, to_upper, replace_all, etc. So it's worth learning the library to boost the C++ string skills.

Example:

Let us take a C++ code to demonstrate the use of boost::algorithm::one_of_equal() method:

Output:

String contains vowel
Vector does not contain 5

Example 2:

Let us take another C++ code to demonstrate the use of boost::algorithm::one_of_equal() method:

Output:

Vector contains 3
Vector does not contain 7  

Conclusion:

The boost::algorithm::one_of_equal() function is an algorithm that provide Boost C++ libraries for working with strings and collections.

It enables us to determine whether a specified string or collection, such as a vector or array, contains at one occurrence of any characters we specify. Here are some important points to remember about this function;

• It performs a search within the string or collection to identify if it contains any of the characters.
• The function returns a value indicating whether a match was found.
• By default, the search is case-sensitive.
• This function works effectively for both strings and collections like arrays and vectors.
• It proves useful in scenarios such as checking for vowels, special characters validating passwords and more.

Let's take a look at some examples of how this function can be utilized;

1. Verifying if a string includes vowels.
2. Ensuring that passwords meet the complexity criteria.
3. Checking if CSV data contains characters.
4. Determining whether a vector<int> contains a number.

In summary, using the one_of_equal() method allows us to check for matches easily from a set of possibilities within strings and collections. It simplifies the process by encapsulating the logic of searching for matches in one call, requiring explicit loops and conditions.

The Boost String Algorithms library offers valuable functions for text processing, manipulation and validation tasks. It serves as an addition to the C++ library for efficient string handling.