Is it good practice to reference each constant line?

Question

Code A:

string a = "Hello World";

for (int i=0; i<1000000; ++i) 
     const string b = a;

Code B:

string a = "Hello World";

for (int i=0; i<1000000; ++i) 
     const string &b = a;

If I ran 2 codes separately and measured the processor time, code B was about 2.5 times faster than code A.

Except primitive types, such as char, int, float... I learned that quickly get a link to the original, but not copy it.

Although in most cases the difference is almost not taken into account, can it be considered good practice to always refer to a type const string(and other non-primitive types)?

Answer 1

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Answer 2

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