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Why Class String Doesn’t Have an Implicit Conversion to char *

Why Class String Doesn’t Have an Implicit Conversion to char *

The standard class string (unlike MFC CString for example) doesn’t have a char * conversion operator for two reasons. First, implicit conversions can cause undesirable surprises when you least expect them. Legacy C code is combined with new C++ code in many systems. In its pre-standardized form, C used char * as generic pointers (void* was added much later). You can imagine what chaos an implicit conversion to char* can inflict in such systems. The other reason is that C strings are null terminated, whereas the underlying representation of a string object is implementation-dependent. An implicit conversion of a string object in a context requiring a null-terminated array of characters can be disastrous. For these reasons, the C++ standardization committee did not include a conversion operator in class string. When you need to do such a conversion, you can call string::c_str() explicitly.

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