Error "cannot convert 'std::basic_string<char>' to 'const char*' for argument '1' to 'int system(const char*)'"

c++, char, string, system

Solution

The type of expression

" quickscan.exe resolution 300 selectscanner jpg showui showprogress filename '"+name+".jpg'"

is `std::string`. However function system has declaration

int system(const char *s);

that is it accepts an argumnet of type `const char *`

There is no conversion operator that would convert implicitly an object of type `std::string` to object of type `const char *`.

Nevertheless class `std::string` has two functions that do this conversion explicitly. They are `c_str()` and `data()` (the last can be used only with compiler that supports C++11)

So you can write

string name = "john";

system( (" quickscan.exe resolution 300 selectscanner jpg showui showprogress filename '"+name+".jpg'").c_str() );

There is no need to use an intermediate variable for the expression.

Problem

Original source