How do I solve this integral

Question

How do I solve this integral (expectation value) : $$\int_{-\infty}^{\infty} \psi (x)^* \hat p \psi (x)\,\text{d}x.$$ where the $\hat p =-i\hbar \frac {\partial}{\partial x}$ is an operator and $\psi (x)$ is the wave function.