testRe ()

testRe(re): ((x) => boolean)
Test string against regular expression.
Parameters
- re: RegExp
Returns ((x) => boolean)
- - (x): boolean
  - Parameters
    - x: string
    Returns boolean
Example
```
testRe(/a/)('bac') // true
testRe(/a/)('xxx') // false

opt('abc').map(testRe(/b/)).orFalse() // false
```
- Defined in Opt.ts:3237