定义变量与模板

Question

In a project, we are creating files to be able to switch languages, during run-time, between English and French.

What are the pros and cons to using defines versus template of constant variables.

#define TRAINABLE_LABEL "Trainable:"
#define TRAINABLE_ONE "Easily trainable"
#define TRAINABLE_TWO "Moderately trainable"
#define TRAINABLE_THREE "Highly trainable"

In template:

const QString TRAINABLE_LABEL = "Trainable:"
const QString TRAINABLE_ONE = "Easily trainable";
const QString TRAINABLE_TWO = "Moderately trainable";
const QString TRAINABLE_THREE = "Highly trainable";

Answer 1

First of all: why do you call it templates?

With aa simple #define you are not really protected against redefition of a certain macro, typeness, etc. So macros for these things should be avoided.

Best way would probably be to use constexpr char* . This gives you the same behaviour as a macro and will issue an error when some variable is redefined.