Shorthand for the int.TryParse(string, out int value) pattern, useful when the C# 8 "Nullable Reference Types" feature is enabled.

Maybe.cs

using System;
using System.Diagnostics.CodeAnalysis;

public static class Maybe
{
    public static bool Try<T>(Func<T> maybeGetValue, [NotNullWhen(true)] out T output)
    {
        output = maybeGetValue();

        return output != null;
    }

    public static bool Try<TInput, TOutput>(Func<TInput, TOutput> maybeGetValue, TInput input, [NotNullWhen(true)] out TOutput output)
    {
        output = maybeGetValue(input);

        return output != null;
    }
}

//Usage:

using static Maybe;
using static System.Environment;
...
if (Try(GetEnvironmentVariable, variable, out value))
{
    //GetEnvironmentVariable(variable) returned a non-null value.
    //The compiler knows that `value` is not null in this block.
}
else
{
    //GetEnvironmentVariable(variable) returned a null value.
    //The compiler knows to warn about possibly-null `value` in this block.
}