Found the following significant warnings:
  cts.cpp:27:45: warning: 'bool arma::is_finite(eT, const typename arma_scalar_only<eT>::result*) [with eT = double; typename arma_scalar_only<eT>::result = double]' is deprecated: change arma::is_finite(val) to std::isfinite(val) [-Wdeprecated-declarations]
  cts.cpp:63:45: warning: 'bool arma::is_finite(eT, const typename arma_scalar_only<eT>::result*) [with eT = double; typename arma_scalar_only<eT>::result = double]' is deprecated: change arma::is_finite(val) to std::isfinite(val) [-Wdeprecated-declarations]
  cts.cpp:328:36: warning: 'bool arma::is_finite(eT, const typename arma_scalar_only<eT>::result*) [with eT = long long unsigned int; typename arma_scalar_only<eT>::result = long long unsigned int]' is deprecated: change arma::is_finite(val) to std::isfinite(val) [-Wdeprecated-declarations]
  mmp_c.cpp:215:29: warning: 'bool arma::is_finite(eT, const typename arma_scalar_only<eT>::result*) [with eT = double; typename arma_scalar_only<eT>::result = double]' is deprecated: change arma::is_finite(val) to std::isfinite(val) [-Wdeprecated-declarations]
  mmp_c.cpp:215:58: warning: 'bool arma::is_finite(eT, const typename arma_scalar_only<eT>::result*) [with eT = double; typename arma_scalar_only<eT>::result = double]' is deprecated: change arma::is_finite(val) to std::isfinite(val) [-Wdeprecated-declarations]
  mmp_c.cpp:216:41: warning: 'bool arma::is_finite(eT, const typename arma_scalar_only<eT>::result*) [with eT = double; typename arma_scalar_only<eT>::result = double]' is deprecated: change arma::is_finite(val) to std::isfinite(val) [-Wdeprecated-declarations]
  mmp_c.cpp:216:72: warning: 'bool arma::is_finite(eT, const typename arma_scalar_only<eT>::result*) [with eT = double; typename arma_scalar_only<eT>::result = double]' is deprecated: change arma::is_finite(val) to std::isfinite(val) [-Wdeprecated-declarations]
  skel_helper.cpp:201:41: warning: 'bool arma::is_finite(eT, const typename arma_scalar_only<eT>::result*) [with eT = double; typename arma_scalar_only<eT>::result = double]' is deprecated: change arma::is_finite(val) to std::isfinite(val) [-Wdeprecated-declarations]
See 'd:/Rcompile/CRANpkg/local/4.6/Rfast2.Rcheck/00install.out' for details.
* used C compiler: 'gcc.exe (GCC) 14.2.0'
* used C++ compiler: 'g++.exe (GCC) 14.2.0'