src/Tokenizer/TokensAnalyzer.php
public function isUnarySuccessorOperator($index)
    {
        static $allowedPrevToken = [
            ']',
            [T_STRING],
            [T_VARIABLE],
            [CT::T_DYNAMIC_PROP_BRACE_CLOSE],
            [CT::T_DYNAMIC_VAR_BRACE_CLOSE],
        ];

        $tokens = $this->tokens;
        $token = $tokens[$index];

        if (!$token->isGivenKind([T_INC, T_DEC])) {
            return false;
        }

        $prevToken = $tokens[$tokens->getPrevMeaningfulToken($index)];

        return $prevToken->equalsAny($allowedPrevToken);
    }
public function isUnarySuccessorOperator($index)
    {
        static $allowedPrevToken = [
            ']',
            [T_STRING],
            [T_VARIABLE],
            [CT::T_DYNAMIC_PROP_BRACE_CLOSE],
            [CT::T_DYNAMIC_VAR_BRACE_CLOSE],
        ];

        $tokens = $this->tokens;
        $token = $tokens[$index];

        if (!$token->isGivenKind([T_INC, T_DEC])) {
            return false;
        }

        $prevToken = $tokens[$tokens->getPrevMeaningfulToken($index)];

        return $prevToken->equalsAny($allowedPrevToken);
    }
Checks if there is an unary successor operator under given index.

@param int $index

@return bool