c – 为什么断言不起作用？

这是代码：

#include <Rcpp.h>
#include <iostream>
#include <assert.h>
#include <stdio.h>

using namespace Rcpp;


// [[Rcpp::export]]
double eudist(NumericVector x, NumericVector y) {
    int nx = x.size();
    int ny = y.size();
    std::cout << nx << '\n' << ny << std::endl;
    assert(nx == ny);

    double dist=0;
    for(int i = 0; i < nx; i++) {
        dist += pow(x[i] - y[i], 2);
    }

    return sqrt(dist);
}

在将其获取到R之后,我得到以下结果,显然在出现错误时它不会中止：

#////////////////////////////////////////////////////
sourceCpp('x.cpp')
#////////////////////////////////////////////////////
eudist(c(0, 0), c(1, 1))
2
2
[1] 1.4142
#////////////////////////////////////////////////////
eudist(c(0, 0), c(1, 1, 1))
2
3
[1] 1.4142

解决方法:

请注意,对于CRAN上载,明确禁止使用assert()等.从CRAN Repo Policy页面引用：

The code and examples provided in a package should never do anything
which might be regarded as malicious or anti-social. The following are
illustrative examples from past experience.

• Compiled code should never terminate the R process within which it is running. Thus C/C++ calls to assert/abort/exit, Fortran calls to
  STOP and so on must be avoided. Nor may R code call q().

所以关于调试模式的答案在技术上是正确的,但是请注意,如果您打算在某个时候上传CRAN,则不应该使用它.

标签：c,r,rcpp
来源： https://codeday.me/bug/20191006/1862684.html