How to concatenate Two 2-byte registers ?

Modbus Register 1  -   value1 (16 bits in length, contains bits 0 to 15)
Modbus Register 2  -   value2 (16 bits in length, contains bits 16 to 31)

short response_buffer[128];   // contains modbus register values

response_buffer[0] contains value1.  response_buffer[1] contains value2.

long result;

/* Is this solution correct ? */
result = (  (long)  ( response_buffer[0] ) +  (long) (response_buffer[1] << 16) ) ;

/* if above solution is correct, can it be simplified ? */
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It is correct - yet the only room to simplify that I see would be to use a bitwise OR (which usually also would be a tad bit faster than an addition):

result = (  (long)  ( response_buffer[0] ) |  (long) (response_buffer[1] << 16) ) ;

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