C++ Create a program that reads a simple arithmetic expression and evaluates it. More precisely, the program reads from the user a line of text that’s supposed to contain two numbers separated by an...

C++

Create a program that reads a simple arithmetic expression and evaluates it. More precisely, the program reads from the user a line of text that’s supposed to contain two numbers separated by an arithmetic
operator, as in:

                           35.6 + 12

The program then prints back the expression and its value, as in:

                      35.6 + 12 = 47.6

The program should verify that the input line contains two numbers, one operator and nothing else. There can be whitespace before the first number, after the second number and between each number and the operator.
The operator can be either +, −, *, or /. In case of an error, the program should print:

                                       "Invalid expression"

and quit.
When the program prints the expression, there should be no whitespace
before the first number and there should be exactly one blank space before
and after the operator and the equal sign.
Use string streams.