To evaluate the integral \( \int_{0}^{1} (2x + 1) \, dx \), find the antiderivative of \( 2x + 1 \):
\[
\int (2x + 1) \, dx = \int 2x \, dx + \int 1 \, dx = x^2 + x + C
\]
Apply the limits from 0 to 1:
\[
\left[ x^2 + x \right]_{0}^{1} = (1^2 + 1) - (0^2 + 0) = 1 + 1 - 0 = 2
\]
Thus, the value of the integral is:
\[
{2}
\]