fix warnings

1 files changed, 5 insertions, 5 deletions

diff --git a/include/countries.hpp b/include/countries.hpp
index 1595b85..de91dab 100644
--- a/include/countries.hpp
+++ b/include/countries.hpp
@@ -39,14 +39,14 @@ namespace country {
     s32     get_count();
     const char*   get_code_by_index(s32 index);
 
-    time_t  get_default_invoice_expire_duration(char* country_code);
+    time_t  get_default_invoice_expire_duration(const char* country_code);
 
     bool    is_EU(const char* country_code);
     bool    is_enabled(const char* country_code);
     bool    tax_is_implemented(const char* country_code);
-    void    fill_tax_report_with_categories(char* country_code, tax_report* report);
-    bool    add_billing_item_to_tax_report(char* country_code, tax_report* report, invoice* inv, billing_item* item);
-    float   calculate_tax_report_final(char* country_code, tax_report* report);
-    time_t  get_invoice_date_to_use_for_tax_report(char* country_code, invoice* inv);
+    void    fill_tax_report_with_categories(const char* country_code, tax_report* report);
+    bool    add_billing_item_to_tax_report(const char* country_code, tax_report* report, invoice* inv, billing_item* item);
+    float   calculate_tax_report_final(const char* country_code, tax_report* report);
+    time_t  get_invoice_date_to_use_for_tax_report(const char* country_code, invoice* inv);
     u32     get_available_tax_rates(const char* country_code, tax_rate* buffer, u32 buffer_size);
 }